Use the divisor/remainder for the WaitForMscOML call if a wait_interval is passed. Allows for testing of the WaitMSC paths in the server & DDX.
A few of my programs were using the client string in addition to the main extensions string to see if a feature was present. Correct this to only check for the currently available and working extensions.
Add program to test glXSwapBuffersMscOML behavior. Based on glsync.c.
