feature added:

- add an entry forceRenderMethod=1 in vba.ini to force using DirectDraw driver (thanks awi´s suggestion)
- force to stop emulation before switching sound emulation on/off
- add an entry saveMoreCPU=1 in vba.ini for slow computer to save more CPU power

bug fix:

[mikoxc] when sound is disable, vba load a game then crashed
- fix a bug in PCM interpolation module

[mikoxc] VBA run a game with sound disable, after load a real-time save file, VBA crashed
- fix another bug in PCM interpolation module

[bohdy] 6.3 still runs at half framerate in automatic mode, just like if frameskip 1 was selected.
- fix a bug in automatic frame rate control

[Squaresoft74] On the top and left sides of the screen i get blue lines that weren´t there with previous builds.
- not crop a pixel around the border of output image