Bug: Emulator doesn't render on some drivers.

[indigodarkwolf]

See also: (Discord)

I'm walking through the debugger. It's something related to OpenGL. glGetSynciv is always coming back GL_UNSIGNALED and glClientWaitSync is always coming back GL_TIMEOUT_EXPIRED. Both of those conditions skip the rendering step. Looks like maybe a driver thing. Yup, when I remove both USE_GL_GET_SYNC and USE_GL_CLIENT_WAIT_SYNC it works.

The fix I would like to see:

• Add a bool to the options struct in options.h to toggle vsync. Default to false.
• Add an appropriate command-line flag to enable the bool in options.cpp and store its setting in the ini file.
• Use the new bool to choose whether to attempt to execute the vsync code in display_process().

[indigodarkwolf]

This was eventually confirmed to fix the known problem cases where Box16 wasn't rendering. Thanks again!