DGen/SDL v1.29 Changelg:

* Reduced CPU consumption.
* Prevented CZ80 from crashing when handling invalid code.
* OpenGL: added configuration option to force square textures.
* OpenGL: fixed non-power of two texture size issue from v1.28.
* Fixed save files to manage YM2612 timers properly.
* Fixed the way files are opened relative to DGen´s home directory.
* YM2612 timers are now managed externally by DGen.
* Removed unused support for M68KEM.
* Refactored memory handling, frame generation and initialization routines.
As a side effect, DGen can run more games now.
* Fixed remaining bugs in Z80 and M68K hot swapping code.
* Updated AUTHORS file.
* Added BUGS file for unresolved emulation bugs.
* Imported hqx filters. hq2x is available for 15/16 and 32 bit, hq3x and
hq4x are only available for 32 bit modes.
* Refactored graphics output functions. Filtering and scaling are now
in separate functions and new filters can be added easily.
* Improved joystick devices configuration.
* Fixed ASM files to ensure non-executable stack on ELF targets.
* Merged OpenGL and normal fonts to remove redundant code. There are now
three fonts available: 7x5 (original OpenGL font), 8x13 and 16x26.
* Fixed other minor bugs.