update README
remove GC stop/start hack
update DebugGfx docs with better description and info about 4096 limit, clear stale gfx before processing each tick instead of before drawing
when game paused and lost focus, set frame rate to 5 to make other apps smoother
print errors to output consoles for ships/stages that try to draw too many debug gfx
update Makefile and samples/API version to 1.1.3
change 'Error' to 'Warning' in messages about too many gfx