February 2015 - version 2.0
===========================

In release 2.0 of lfe, there is better support for matrices as
covariates, both on the left and right hand side of the equation, and
in the instrumental variable specification.  It is also possible to
explicitly include multiple left hand sides, e.g. with formulas like
'y|z|w ~ X |f1 + f2'.  The content of 'felm' objects have changed
slightly to accomodate this, and generic functions like vcov() and
coef() have gained an extra argument 'lhs' to specify which left hand
side to retrieve information about.

Two new functions, waldtest() and condfstat() have been included to
test linear restrictions on parameters, and to compute conditional F
statistics to test for weak instruments in the IV estimations.
Observations with missing values are now correctly removed in IV-estimations.

The old syntax, with 'G()' to specify factors to project out, has been
deprecated. It still works, but will yield a warning.  Similarly with
the arguments 'iv' and 'clustervar' to felm().


December 2014 - version 1.8
===========================

Two new functions were added, fevcov() and bccorr(), to compute
limited mobility bias corrections for covariances (and correlations)
between high dimensional factors.  See citation('lfe') for reference
to article describing it.


March 2014 - version 1.7
========================

Support for multiway clustering added.  Multiway clusters are specified
in the 4th part of the formula, like y ~ x | f1+f2 | 0 | c1+c2


December 2013 - version 1.6
===========================

Added support for projecting out interactions between continuous covariates and factors.


October 2013 - version 1.5
==========================

Version presented in R-journal article. (See citation('lfe') for reference)