0.4.0:

- FEATURES/IMPROVEMENTS:

 - Added option to process directories recursively,

 - Added support for various GIF bit depths.

 - Added support for grayscale JPG.
 
 - Added multiprocessing. JPG, PNG and GIF file generation now runs in
   separate processing, improving speed significantly on multicore machines.
   User can control multiprocessing through the --prc-mult option (see --help).
   Batches of files can also be divided to multiple processes, improving
   speed further.

 - Added an automated test suite to check for most obvious bugs.

 - Added benchmark and profiling scripts
 
 - Handling more input/output errors now.

 - Removed stats module due to it being a complete mess.

 - Removed --fill and --bg-color options, deprecated 
   other resizing options.

 - Speed improved significantly in big file benchmark 
   but worsened somehwhat in many files benchmark:
   Pentium Dual Core 1.73 GHz 4GB RAM:
   benchmark :   0.3.2:    0.4.0:
   many_files:   618.04s   900.13s  +45.64%
   big_file  :   1215.92s  590.10s  -51.47%
   total speedup: 18.74%

- BUGFIXES:

 - IMGCrush now detects if temporary directory already exists and
   creates new one if it does, so multiple instances of the program
   can run at the same time.

 - Fixed bugs with handling of filenames with spaces.

 - Fixed a bug that sometimes resulted in suboptimal output (especially 
   in lossless quality mode)

- OTHER:
 
 - Cleaned up and documented a lot of code.   
 
 - Moved from ImageMagick to GraphicsMagick dut to its better speed.