HISTORY:
Layer branch:
- added support for layered graphics (main use case: multiaxis + layers)

1.5.2:
- added support for second colormap in mesh plots (mesh/interior colormap name)
- contour plots: added ability to provide list of discrete labels (mesh/levels)
- fixed a couple of bugs
- fixed incompatibility of lualatex and shader=interp

1.5.1:
- more operations for FPU library (==, !=,<=,>=,?)
- fixed bug in usage of decorations in \addplot
- bugfix for contour prepared format=matlab
- added 'const plot mark mid' and 'jump mark mid' plot handlers
- nodes on a plot (\addplot ... node[pos=<fraction>] {};)
- 'trim axis group left' and 'trim axis group right'
- bugfixes for polar axes and log+stacked plots
- added style 'log ticks with fixed point'
- introduced patched tikz paths to simplify circles and ellipses within an axis
- patchplots lib: patch type=polygon
- some more bugfixes

1.5:
 - Contour plots,
 - Histograms,
 - Quiver plots,
 - patch plots (library)
      - Triangle Meshes
      - Bilinear Elements
      - Quadratic Triangles
      - Biquadratic Quadrilaterals
      - Coons Patches
 - Discrete colorbars,
 - Table sorting,
 - Linear regression,
 - Ternary diagrams,
      - Tieline Plots
 - Smith Charts
 - Polar axes,
 - Empty lines in input files result in interrupted plots,
 - PDF user defined coordinate mouse popups
 - CMYK colormaps and shadings,
 - new markers and cycle lists
 - access to axis limits,
 - \addplot3 graphics: pgfplots draws an appropriate axis for a three-dimensional(!) external png graphics
 - 3D axes: support to provide explicit unit vectors:
 	- explicit unit vectors
	- explicit unit vectors which are uniformly rescaled to match width/height
 - 3D axes: improved support for unit vector ratios
 - improvements of the groupplot styles
 - preliminary support for (2d) bar plots in 3d axes
 - new shader 'faceted interp'
 - table package: 
 	- 'every nth row' style
	- 'comment chars' key to define comment characters in input files
	- 'skip first n' style
 - lots of smaller bugfixes (see ChangeLog for details)


1.4.1:
- improved compatibility to gnuplot 4.4

1.4:
Version 1.4 contains several new features, mostly work on details.
It fixes many bugs and provides the following improvements:
- detached legends 
- detached colorbars
- ybar (and similar plots) can now be mixed with other plot types 
  like line plots.
- improved legend formatting
- added 'restrict x to domain*' which cups coordinates outside of a specified domain (same for y and z)
- Added support for linear regression
- Inline tables,
- Lots of bug fixes

The next version will make a greater step when it is stable.


1.3.1:
Version 1.3.1 is a bugfix release containing
- improved parametric plots with gnuplot
- improved normalsize, small and footnotesize scale styles and added tiny
- a lot of bugfixes

1.3:
- improvements for two dimensional visualization, among them
	- axis equal,
	- color bars,
	- nodes near coords,
	- jumps in plots,
	- improved description positioning, 
	- reverseable axis directions,
	- simpler alignment of adjacent axes,
	- units and a simplified user interface,
- new three dimensional line, scatter, mesh and surface plots,
- a copy of the automatic pdf externalization library, 
- an improved manual enhanced with a lot of pdf cross references.

1.2.2:
- fixed a problem with the samples key, 
- provides some smaller fixes and some manual improvements.
- added plot graphics.

1.2:
- completely rewritten math expression parser with extended data range, 
- colormaps for scatter plots
- fine tuning for plot parameters.
- table package has been extended and is now a fully featured table typesetting, computing and postprocessing tool.