GL_EXT_win32_keyed_mutex
http://www.opengl.org/registry/specs/EXT/win32_keyed_mutex.txt
GL_EXT_win32_keyed_mutex

	GLboolean glAcquireKeyedMutexWin32EXT (GLuint memory, GLuint64 key, GLuint timeout)
	GLboolean glReleaseKeyedMutexWin32EXT (GLuint memory, GLuint64 key)