Log Message:
Update prboom to version 2.2.2

Changes from v2.2.1 to v2.2.2
- more demo sync problems for original Doom and Boom fixed
- added changeable samplerate for soundmixing
- added fullscreen/window toggle in option menu
- added double buffering
- floor rendering made more accurate
- Win32 config file handling fixed
- fix endian conversion problem on Linux/PPC