GUAC-852: Make checks for FreeRDP libs non-fatal. Additionally check for libfrerdp + libfreerdp-client (replaces libfreerdp-core on master).
GUAC-852: Add bitmap_decompress implementation (partial stub - will not work with older FreeRDP).
GUAC-852: Use freerdp_convert_gdi_order_color() for color conversion.
GUAC-852: Use freerdp_image_copy instead of freerdp_image_flip.
GUAC-852: Store raw ARGB32 palette internally, for future use in conversions.
GUAC-852: Refactor bitmap_decompress within guac_rdp_bitmap_decompress.
GUAC-852: Use old bitmap_decompress if no codecs in context. Restore use of freerdp_image_flip.
GUAC-852: Abstract away color conversion.
GUAC-852: Use rdpContext.codecs as a basis for determining whether FreeRDP uses _aligned_malloc() internally.