Fix OSX fullscreen issue.
Updates project (for OS X) to SDL v1.2.15.
Possible issues:
 - SDL_SetGamma seems to be bugged? If a user is having issues have them do /gamma 100 and restart AC
 - ???
Fixes OpenAl Error (A004) upon shutdown.
Basically removes the buffers _after_ stopping all sounds.
Updating SDL to 1.2.15

Updates header files in source/include
Updating SDL_image for OS X
Change position of "SCROLL/SPACE..." HUD messages

Now "SCROLL/SPACE..." messages will be visible on the right side
of display, in every standard aspect ratio.
Fix for conver_mapconfig.sh: Allow spaces in filenames.
Install/Remove menuitem script re-added/replaced.
Changed my mind - let removal of existing .desktop items to be more permissive.
Script now compatible with KSH/dash.
removed CUBE_TODO.txt

Has been outdated for nine years and is apparently a huge distraction for
wannabe new coders.
server: remove forbidden word blacklist

This feature does more harm than good, since it's very easy to abuse.
server: simplify SV_TEAMTEXT and SV_TEXTPRIVATE