BSAVE:
- Add bitsperpixel parameter to request BMP bit depth
- change default bpp for 32-bit images from 24 to 32
- return ILLEGALFUNCTIONCALL error for parameter problems in fb_GfxBsaveEx() instead of FILENOTFOUND
- update changelog
rtlib: Apply patch #32 and fix some potential compiler warnings
gfxlib2: Fix uninitialized var warnings in fb_GfxPut()