OpenGL2: Parallax corrected cubemap (cheaper trick)
Revert "DMA 44100Hz needs more memory for sound buffers"

This reverts commit 0e6632f464c08dcb76f26a52f33d97228e64fda1.

Cause crashes if com_soundMegs is 32.
Fix FS_FOpenFileReadDir non-zero file handle when file not found in pk3

If a pk3 search path is passed to FS_FOpenFileReadDir, a non-zero
file handle is returned if file is not found. This causes incorrect
behavior in FS_ReadFileDir (when a pk3 search path is passed in)
which only checks file handle, not length, for seeing if file exists.

I don't know of any issues in ioq3 caused by this.
#6095: OpenGL2: Use areamask and leaf cluster for PVS when VIS is missing.
Merge branch 'master' of https://github.com/ioquake/ioq3