1. Fix style for channels/rdpgfx/server/rdpgfx_main.c according to scripts/format_code.sh
2. Refactor and introduce APIs to allow rdpgfx server channel running in existing thread (similar to rdpsnd)
1. Fix stream leak in rdpgfx
2. Make src data const in zgfx. Harden zgfx to be independent to byte order
3. Fix written bytes return value in channel write
4. Add check for return value in shadow_client.c
5. Add gfx callback to send surface command with frame marker pdu.
6. Check remain length for recv subroutine
7. Fix compile errors
