libfreerdp-gdi: start optimizing gdi bitmap update
libfreerdp-gdi: fix and cleanup new bitmap update code
xfreerdp: optimize bitmap updates
libfreerdp-gdi: fix bitmap caching
libfreerdp-cache: fix 15bpp
wfreerdp: fix gdi usage
libfreerdp-gdi: add RDP8 graphics pipeline support
Merge pull request #2097 from awakecoding/egfx

GDI Bitmap Update Optimization
Replaced logging in libfreerdp with wlog defines.
Using wlog for channel logging now.
Fixed compiler warnings and broken callback in urbdrc.
Fixed compiler warning.
Using wlog for logging in clients now.
Using wlog for server now.
Removed obsolete headers and defines.
Fixed compiler warnings.
Fixed possible memory leak.
Removed remaining printf and DEBUG_* usages.