clean up image loading a bit. gets rid of useless "Passed NULL data source" or PhysFS file not found errors
load the girder.png of a theme a maximum of 1 times (minimum of 0), instead of once per generated bridge
small hat loading tweak
here a personal experimental mockup of how I imagine wrapping world edges should look like. bouncing one could be similar just with mirrored stuff.  please test and share opinion. note: you might wanna disable auto-cam
use cScaleFactor where I incorrectly used the variable zoom in the past. i was young and needed the money