config: add 2 parameters to allow disabling s3tc/auto mipmap gen
wpthread: add support for named semaphores (required for macosx compat)
openal, ogghack: remove direct use of __APPLE__ macro (replace with
OS_MACOSX)
GraphicsSetupHandlers.cpp: fix incorrect usage of OS_ macros (they're
always defined, so the test should be if their value is != 0)
This was SVN commit r5316.