Switched to SDL 2.0.
Multi-threading support enabled, although I'm still working out the glitches.
Optimized the primary rendering thread.
Added "open" and "closed" to RenderQueue:
If a queue is open, the threads will loop, waiting for more input.
If a queue is closed, the threads will terminate when it's empty.
Changed AA to match, but performance has suffered.
Removed unnecessary code from AA thread function.
Removed open/close from render queue. It was a bad idea.
Fixed formatting.
Removed debug flag.
Changed all "r_screen" to "screen" because why not?
Split renderqueue into its own file.
Spun off renderqueue.cpp.
Cleaned up mutexes.
Forgot to render the first row!