Fixed GL error with SDL on startup if not using nvidia card.
Changed _isnan to Q_isnan for OSX.
Fixed MP renderer for 64-bit builds.
Removed the use of DWORD in icarus code, and also changed bad uses of long
to int - while there are no problems of using long in 64-bit builds for
Windows (as they remain 32-bit in size), other OSs expand long to 64-bits
under a 64-bit environment.
Corrected and improved error messages when a library cannot be found.
Removed last bits of DWORD from icarus.
Fixed loading of icarus scripts for 64-bit builds.
Removed very last bit of DWORD usage from MP.
Merged d78f602f41 to SP.
Fixed inverted movement using keyboard when in_joystick is 2.
(This also affected mouse)