Enable scissor optimization

Used to enable or disable scissor optimization. The accepted values are true and false. When scissor optimization is enabled, OpenGLRenderer attempts to minimize the use of scissoring by selectively enabling and disabling the GL scissor test.

When the optimization is disabled, OpenGLRenderer keeps the GL scissor test enabled and changes the scissor rect as needed. Some GPUs (for instance, the SGX 540) perform better when changing the scissor rect more often than enabling or disabling the scissor test often.