- alternative configuration using GLEW to get extension functions. This requires GL 2.0, though so it won't be promoted to the mainline for the time being.
- removed all pre GL 2.0 support.
Merge branch 'master' into GLEW_VERSION
- got rid of a lot of stuff that's no longer required with GLEW.
- replaced GLUs texture scaling with our own function. This is only used to scale down textures larger than what the hardware can handle so we do not need a dependency to an essentially deprecated library for it.
Merge branch 'master' into GLEW_VERSION
fixed some issues with reviving monsters

- fixed: Thing_Raise didn't properly set the spawn health.
- fixed: Thing_Raise did not the CanRaise state flag.
- fixed: Reviving a monster must also reset the damage type.
- fixed: Thing_Raise reset the actor after calling the raise state, but it should be before, just as the Archvile code is doing.
- consolidated some common code of Thing_Raise and Archvile resurrection into AActor methods.
Stop NetUpdate from corrupting demo playback
- removed redundant variable.
- typo in resurrection code.
made some changes to turn the CF_INTERPVIEW flag when changing angles into an op-in feature instead of making it automatic.
Merge branch 'interpview_optin'
- added new ChangeActorAngle/ChangeActorPitch ACS functions because the new required 'interpolate' parameter cannot be added to the existing SetActorAngle/SetActorPitch functions without breaking old scripts.
- removed the __asm nop breakpoints for debugging. They not only do not work on non-MSVC but also not on 64 bit.
Merge branch 'master' of https://github.com/rheit/zdoom
- fixed: memory allocation for file names in 7z archives was broken. Changing it to use TArray instead of alloca makes it work.
Merge branch 'master' of https://github.com/rheit/zdoom
- changed sound lookup for ZSDF dialogues so that it first checks the svox/ namespace before using the global one.
Merge branch 'master' of https://github.com/rheit/zdoom
Merge branch 'master' into Glew_Version_For_Real
- changed rendering of glowing walls so that it doesn't require an additional vertex attribute, just pass the floor and ceiling planes as uniforms.
Set output alpha in shader to 1.0, to avoid hall-of-mirrors defect reported by Ben Johnson