Increase particle system limits.
Replace std::map with std::unordered_map in PropertyMap
Remove feature test macros from qcommon.h
Detect a missing opusfile at configure time. Fixes #467.
Implement soft particle shader.

The new shader keyword depthFade specifies the virtual "thickness" of
the sprite.
Add depthFade to the acid tube acid shader
Attempt to mitigate #409. Add logging for when it does happen
Orient sprites toward view center.
Add depthFade to the booster spores shader.
Merge remote-tracking branch 'origin/ejector-limit'
Avoid division by zero in Tess_SurfaceSprite.
Name the magic number in Tess_SurfaceSprite.
Merge branch 'master' into renderer
Merge remote-tracking branch 'origin/sprite-orientation' into renderer
Attempt to fix interpolation of fadeDepth.

This interpolation really shouldn't be perspective corrected.
Version bump to Alpha 33
Merge branch 'rocket-optimization'
Revert "Increase particle system limits." This prevents the game from starting on Windows.

This reverts commit 5633b82ffb7260f314e3194f6c16ba1292c25448.
Turn DropClientMsg into a SyncMessage because it will call back into the VM
Version bump to Alpha 33.1