another attempt at proper retina texture scaling
retina scaling fixed, thanks @aroth for testing
camera fix to center levels smaller than screen
game now handles images loaded after preloading phase, resize/refresh bug fix
bug fixes for recent changes
incorrect tile shape extraction bug fix (thanks @aroth for finding)
first pass on fix for #113
Merge remote-tracking branch 'upstream/dev' into conversation-tree
trying to resolve resize issues in conversation trees