Fixes a threading issue which caused QB64 to intermittently crash when using hardware commands
(Same threading fix yet to be applied to Linux)
Fixes problem in last update which prevented _OPENHOST/_OPENCLIENT from working (they always returned invalid handle '0')
Fixes 3D perspective issue when 3D rendering into images not the primary display (previuosly the dimensions of the screen/window not the target image were used to determine the aspect ratio)
Corrects dependency detection bug in prev update which rendered _SCREENIMAGE unusable
Implements new command _FPS which limits the maximum hardware fps (primarily for throttling SUB _GL) [default is 60]
Usage example:
_FPS 100
