fix build warning

warning: implicit declaration of function ‘winpr_bitmap_write’
[-Wimplicit-function-declaration]
libfreerdp: always build "MONOLITHIC"

"libfreerdp" consisted of multiple (small) single libraries. If the cmake
option MONOLITHIC was used only one library was build combining all of
the libfreerdp-* libraries.
The only exceptions to this are libfreerdp-server and libfreerdp-client these
are build as separate libraries.

This commit obsoltes non-monolithic builds and makes monolithic builds
the default. The cmake option MONOLITHIC is also removed.
Fix: misc compiler warnings

Seen in Xcode
Merge pull request #2095 from bmiklautz/feat/byemonolithic

Remove non-monolithic builds of libfreerdp
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.