2021-10-25: Ver 0.3-6
  * Change configure.ac for autoconf-2.71
  * Change tests to local in-process (inter-thread) communication transport
    "zmq_inproc".

2021-04-17: Ver 0.3-6
  * Check and add "libzmq>=4.3.0" and "-DENABLE_DRAFTS=ON" options.
  * Add more ZMQ socket options up to libzmq 4.3.4 (may not stable).

2021-02-27: Ver 0.3-6
  * Add more ZMQ socket options.
  * Add timeout for connection in tests.

2021-02-09: Ver 0.3-5
  * Update "conf.sub" and "conf.guess" from CRAN.

2020-12-13: Ver 0.3-4
  * Change "http://" to "https://".

2020-09-07: Ver 0.3-4
  * Fix warning 'char* strncpy(char*, const char*, size_t)' output truncated
    due to "-Werror=stringop-truncation" by gcc 8.3.1
  * Fix a "buf[1]" in zmq.send() call in "R_zmq_sendrecv.r"

2019-07-27: Ver 0.3-4
  * For osx, change "install.libs.R" and "zzz.r.in" for staged installation.

2019-07-10: Ver 0.3-4
  * Roll back to (R >= 3.5.0).
  * Change detection of ZeroMQ library version to "4.2.2" from "4.0.4".
  * Roll detection of ZeroMQ library version to "4.0.4".
  * Block ZeroMQ library version "4.1.6".

2019-05-03: Ver 0.3-4
  * Add "StagedInstall: FALSE" to DESCRIPTION to turn off WARNING in macos.

2019-04-26: Ver 0.3-4
  * Revmoe "^M" from "src/zmqsrc/src/condition_variable.hpp".

2019-04-01: Ver 0.3-4
  * Support REQ/REP sockets in sendfile/recvfile functions.

2019-02-18: Ver 0.3-4
  * Add "R/R_zmq_transfers.r" for transferfing files and directories.
  * Add importFrom utils for zip and unzip.
  * Remove "-Werror" from "src/zmqsrc/configure" to pass "R CMD check".

2019-02-17: Ver 0.3-4
  * Register "R_zmq_send_file" and "R_zmq_recv_file" in "src/zzz.c".
  * Fix Windows binary files transfer problems.

2018-04-30: Ver 0.3-3
  * Change some problems related UTF-8, latin1 TeX inputs, especially for
    TeXLive 2018.

2018-01-27: Ver 0.3-2
  * Add overwrite.shpkg.rpath() for osx.
  * Adjust .onLoad() for osx with ZMQ static library.

2018-01-18: Ver 0.3-2
  * Adjust .onLoad().
  * Add back "src/pkg.m4".

2018-01-07: Ver 0.3-1
  * Test with JuniperKernel.

2018-01-06: Ver 0.3-1
  * Fix uses of osx external static library.
  * Fix get.zmq.conf().

2018-01-03: Ver 0.3-0
  * Disable "zmq_utils.h" because #pragma diagnostics is not needed at all.

2017-12-30: Ver 0.3-0
  * Fix windows conf spacing problems.
  * Adjust contributions in DESCRIPTION.

2017-12-29: Ver 0.3-0
  * A better script for osx is made: overwrite both pbdZMQ.so and libzmq.*.dylib.
  * Remove some initial scripts needed by osx.
  * pbdZMQ.so is now exported too.
  * Appveyor builds are added for windows (i386 and x64).

2017-12-26: Ver 0.3-0
  * Modify and rearrange "install.libs.R" and "zzz.r.in".

2017-12-25: Ver 0.3-0
  * Add libzmq.5.dylib for Mac OSX.
  * Add test.load.zmq().

2017-12-24: Ver 0.3-0
  * Change to ZeroMQ 4.2.2 library.
  * Export ZerMQ flags (CPPFLAGS and LDFLAGS).
  * Add zzz.cpp in zmqsrc/src/ and relevance.
  * Test with external ZeroMQ library.
  * Add vignettes.
  * Add C++ header files to ZeroMQ library.

2017-10-01: Ver 0.2-7
  * Add check eintr to poller.
  * Fix a CRAN warning as
    R_zmq_utility.c:34:24: warning: sprintf writing a terminating nul past
    the end of the destination [-Wformat-overflow=]

2017-07-05: Ver 0.2-7
  * Retire R6/pyzmq-like bindings.

2017-05-14: Ver 0.2-6
  * Add dynamic symbol registration.
  * Add zzz.cpp in zmqsrc/src/ and relevance.

2017-01-11: Ver 0.2-6
  * Move remoter back to Enhances because sodium does not work on CRAN Solaris.
  * Add a fake `ls()` to avoid `rm(list = ls(all.names = TRUE)` to delete any
    hidden pbd objects mainly `.pbd_env` and `.pbdenv`.

2016-12-31: Ver 0.2-6
  * Move pbdRPC and remoter to Suggests.

2016-12-17: Ver 0.2-5
  * Change web address.

2016-12-04: Ver 0.2-5
  * Patch zeromq checking return code problem for sodium_init().
    See the discussion at https://github.com/zeromq/libzmq/issues/1632 and
    https://github.com/zeromq/libzmq/issues/1635 . This causes warning to stop
    because changes were made in new version of libsodium.

curve_client.cpp: In constructor 'zmq::curve_client_t::curve_client_t(const zmq::options_t&)':
curve_client.cpp:51:18: error: ignoring return value of 'int sodium_init()', declared with attribute warn_unused_result [-Werror=unused-result]
     sodium_init();
                  ^
cc1plus: all warnings being treated as errors
Makefile:728: recipe for target 'libzmq_la-curve_client.lo' failed
make[2]: *** [libzmq_la-curve_client.lo] Error 1

    The patch is based on
    https://github.com/zeromq/libzmq/commit/479db2113643e459c11db392e0fefd6400657c9e .

2016-08-06: Ver 0.2-4
  * Export zmq header files.
  * Add get.zmq.cppflags() and get.zmq.ldflags() to "R/get_conf.r".

2016-05-17: Ver 0.2-3
  * Fix build_zmq.in bugs for Fedora/Red Hat GCC (Philipp A.)
  * Try to overwrite pbdZMQ.so path to libzmq.4.dylib in run-time.

2016-04-23: Ver 0.2-2
  * Migrate to Rtools33 and R 3.3.0 for Windows.

2016-01-26: Ver 0.2-2
  * Fix .pbd_env export problem.
  * Fix warning and error problems by tryCatch().
  * Move C_errno to global.

2016-01-25: Ver 0.2-2
  * Add MC option (stop.at.error) to zmq.poll().

2015-12-25: Ver 0.2-1
  * Poller demo and man added and checked.
  * Add multiple parts for send and recv using raw and serialization.

2015-12-20: Ver 0.2-1
  * Add Poll functions.

2015-12-15:
  * Add vignettes for Solaris.

2015-12-10:
  * Solaris works with external ZeroMQ 4.0.7.

2015-11-22:
  * Added verbose option to zmq.sendfile() and zmq.recvfile().
  * Change zmq.sendfile()/zmq.recvfile() to use PUSH/PULL.

2015-11-20:
  * Added zmq.sendfile() and zmq.recvfile().

2015-11-14: Ver. 0.2-0
  * Fix the RPATH problem in  Mac OSX 10.10 Yosemite by using otool and
    install_name_tool after shared libraries are installed in
    "src/install.libs.R".

2015-11-03: Ver. 0.2-0
  * Simplify global environment.

2015-10-24: Ver. 0.2-0
  * Change to common environment, but this will create masking, overwritting,
    and texting problems when other pbdR pacakges are loading.
  * Change again to .pbd_env, .zmqopt_set(), .zmqopt_get(), and
    .zmqopt_init() with huge options rewritting.

2015-10-08:
  * Expanded PyZMQ-like interface.
  * Added address and port validation utilities.

2015-10-02:
  * Take off -rpath $(libdir) from line 598 in
    "src/zmqsrc/src/Makefile.in". (fail)

2015-10-01:
  * Added PyZMQ-like R6 interface.
  * Change to roxygen2.
  * Add vignettes.

2015-09-30:
  * Converted manual to roxygen.
  * Added significant examples to the vignette.
  * Enhanced the README.
  * Cleaned up DESCRIPTION.

2015-09-26:
  * Give Solaris another try.

2015-09-22: Ver. 0.1-1
  * Fix src_Makefile (windows).

2015-09-15:
  * Rewrite configure.ac for version checking (Fedora).
  * Rewrite R/get_conf.r for windows.
  * Fix Mac OSX problem. $(SHLIB) can not be ".so", but on CRAN Mac checks ...

2015-09-14:
  * Check version of pkg-config.
  * Check version of system libzmq.

2015-09-11: Ver. 0.1-0
  * Change to pkg-config and use different installation order.
  * On CRAN.

======================= Log Before Release =====================================
2015-08-30:
  * Change option controlling method. Move from data to new.env.
  * Fix configure and installation.

2015-08-28:
  * Fix windows zzz.r with R_ARCH.

2015-08-15:
  * Add author.
  * Add local to dyn.load in zzz.r.
  * Try to migrate to ZeroMQ 4.1.2, but fail.
  * Add external linked library to ZeroMQ 4.1.2.
  * Add vignettes.

2015-05-30:
  * Clean up, check with new R-devel, and add vignettes.

2015-04-25:
  * Add shellexec.wcc() to active and minimize the new cmd window running
    mpiexec via batch files. No blocking the current windows nor rui.

2015-03-15:
  * Add more zmq_msg_* wrappers and test with pbdCS in win32 and win64.
  * Add vignettes.

2015-03-10:
  * Add some rzmq wrapper functions for pbdCS.
  * Adjust more rzmq wrapper functions.

2015-02-27:
  * Change zmq.recv() to return a list with two elements, buf and len.
  * Add msreader to demo.

2015-02-26:
  * taskvent, taskwork, and tasksink in demo are tested.

2015-02-22:
  * Add more ZMQ functions.
  * wuserver and wuclient are tested.

2015-02-21:
  * Add linking to external library options.
  * Add man and vignettes.

2015-02-20:
  * Mac OSX 10.7 works with shared library.

2015-02-18:
  * No success for Solaris. ZeroMQ can not be built standard alone.

2015-02-17:
  * Both Linux and Windows work with shared library.
  * hwserver and hwclient are tested successfully.

2015-02-16:
  * Change from static library to shared library.

2015-02-xx:
  * Build static library, but check with warnings such as printf, putc, abort.

2015-01-29:
  * First build for pbdZMQ.
  * First try for binaries build of Windows.
