WIP: More flexible memory mapped files.
Fixed many mem-mapped file issues.  Added header entry to file.
More flexible memory mapped files.
Added flip-y to memory map list; changed to per-class worker thread pool in renderers; Fixed demo app status box and BGL presets.
Improved labeling and removed extra status thread.
Added more task-sizes.
Tuned parallel-by-glyph paramemters.
Parallel by glyph seems to perform better with fewer large tasks, while parallel by pixel does better with more smaller tasks.