ggplot2 0.8.5 (2009-XX-XX) ----------------------------------------

New features

* geom_text gains parse argument which makes it possible to display
  expressions. (Implements #50)

* all scales now have legend parameter, which defaults to TRUE. Setting to
  false will prevent that scale from contributing to the legend (Implements
  #27)

* default axis labels and legend titles are now stored in the options, instead
  of in each scale. This fixes a long standing bug where it was not easy to
  set the label for computed variable, such as the y axis on a histogram.
  Additionally, it means default scales are only added to the plot until just
  prior to plotting, instead of the previous behaviour where scales where
  added as layers were added - this could cause problems if you later modified
  the underlying data. (Implements #28)

* coord_equal: when ratio = NULL (the default), it will adjust the aspect
  ratio of the plot, rather than trying to extend the shortest axis.

* x and y positions can be set to Inf or -Inf to refer to the top/right and 
  bottom/left extents of the panel. (Implements #18)

* expand_limits(): a new function to make it easy to force the inclusion of 
  any set of values in the limits of any aesthetic.

New features (minor)

* aesthetics: when _setting_ an aesthetic, you may only set it to a single 
  value.  This was always a good idea, but now it is enforced with an 
  informative error message.
* stat_contour bump up default number of contours
* stat_density2d: make number of grid points used for density estimation 
  user controllable (implements #9)
* geom_bin now allows you to set whether bins used intervals of the form 
  (a, b] or [a, b) with the "right" parameter (implements #20)
* geom_path: linejoin, lineend and linemitre are now user controllable 
  (implements #24)
* scales: all scales check that breaks are supplied if labels are, and 
  that breaks and labels are the same length (implements #40)
* scales: if breaks are a named vector, the names will be used as labels
  (thanks to suggestion by David Kahle)
* scale_colour_gradient, scale_colour_gradient2 & scale_colour_gradientn now
  have formatter argument to match scale_continuous
* updated citation to refer to the ggplot2 book

Bug fixes

* coord_cartesian now correctly sets limits when one or both of the position
  scales are non-linear.  (fixes #17)
* coord_equal: now works with non-linear scales (fixes #13)
* coord_map sets aspect ratio correctly (fixes #4)
* coord_polar correctly combines labels on end of axis if expressions
  (fixes #39)
* coord_trans now respects scale expand parameter (expansion occurs after 
  transformation) (fixes #14)
* facet_grid with scales = "free" and space = "free" now calculates space 
  correctly if the range of the scale is < 1 (fixes #1)
* facet_grid works once more when facetting with multiple variables in one
  direction (fixes #11)
* facet_wrap now sets aspect ratio correctly
* facet_wrap now maintains original order of data
* geom_hline and geom_vline now work with coord_flip (fixes #30)
* geom_path drops missing values at start and end of each line (fixes #41)
* scale_shape_discrete, scale_size_continuous, scale_alpha and
  scale_linetype_discrete added to scales to match naming convention of all
  other scales (fixes #47)
* legends now correctly calculate label widths (fixes #38)
* legends will only merge if both the title and all labels are the same.
  (fixes #16)
* legends: fix for bug #19: Legend with three constraints doesn't work 
* stat_contour & stat_density2d: fix grouping bugs (issue #7)
* xlim, ylim: fix bug when setting limits of discrete scales
