Revert "[SP] Also install jagame/jk2game shared object to the base folder"

This reverts commit 6f8801fd635d33c7a753f23014b259daaa29e604.
[SP] Don't fallback to looking in base for jagame/jk2game.  Fallback to OpenJK.
[MP] Some game dll load function cleanup.
[SP] Fix cg_main.h header guard define.
[SP] Just remove cg_main.h entirely.
[SP] Cleanup/warning fixes for both SP games.
[SP] Fix extern.
[SP] More warning fixes to SP games.
[SP] A couple more warnings.
[MP][OSX] cgame,game,ui dylibs installed into .app
[SP][OSX] jagame installed into .app
[MP] app bundle now with localised name
[SP] app bundle now with localised name
[JK2SP] OSX .app bundle stuff
[JK2SP] Fixed third person weapons not showing
[JK2SP] galak got his face back

only the _off removal was strictly necessary to #ifdef, I wanted to be
safe though
[SP] Remove tr_image_manipulation.
[MP] Remove R_LoadDataImage, R_CreateAutomapImage.
[JK2SP] Another "_off" ghoul2 surface fix
[SP] Removed some RMG files