Log Message:
Update to 0.5.1.
   Changes:
   AUDIO: Added audio Delta-Sigma filter.
   AUDIO: Fixed pseudo stereo mode 2 by disabling noise cycling.
   CODE: Changed default minimum CPU requirement on DJGPP and Mingw32 compiled \ 
builds to i586 (Pentium class), up from i486.
   CODE: Makefile improvements, including automagic dependancy list generation.
   CODE: Centralized all save data functions into 'save.c' and 'save.h'.
   CODE: Split 'misc.h' into 'common.h' and 'types.h'.
   CODE: Renamed 'crc32.c' and 'crc32.h' to 'crc.c' and 'crc.h', respectively, \ 
to allow for future additions to the CRC
   generation API.
   CODE: Fixed version number to read 0.5.1 instead of 0.4.0 - it was broken in \ 
the January 13th WIP release, which was
   supposed to be 0.5.0. x_x
   CORE: Removed x86 optimized core since it's benefits these days are \ 
questionable compared to the overhead it induces.
   GUI: GUI overhaul, partial Unicode support, and more.
   GUI: Added GUI toggle for Zapper emulation.
   GUI: Changed default GUI theme to 'Panta'.
   GUI: Changed display method for backgrounds less than 200 pixels high from \ 
stretched to centered.
   GUI: Fixed background drawing in color depths higher than 8 bits-per-pixel.
   INPUT: Added support for using the mouse as an input device.
   MISC: Added a CPU usage option and subsequently a GUI menu with which to \ 
configure it.
   VIDEO: Added support for 24-bit video modes (fullscreen and windowed).
   VIDEO: Removed outdated 2xSOE blitters.
   VIDEO: Overhauled all remaining blitters and combined multiple blitter \ 
variants together.
   VIDEO: Added new DES and DESii blitters.
   VIDEO: Added makeshift support for HQ2X, HQ3X, and HQ4X.
   VIDEO: Changed default display mode under windowed environments from \ 
fullscreen to windowed; use a platform-specific driver
   or the 'Force Fullscreen' option to override.