Add MSVC SDL 1.2.15 Revision 8040 import libs

(cherry picked from commit 880a7c6becf9072ac721904d155f8929b06b6a32)
OpenGL2: Remove sRGB support, replace with gamma cvars.

(cherry picked from commit 4fe69cb41835575af576d7b67ef1488266141c4b)
Rebuilt MSVC SDL 1.2.15 Revision 8040 import libs

(cherry picked from commit b9b67036f3370b2e5f216eaf5ba68f3461267f02)
Set commit ref after synchro with ioQ3 upstream