Fixed CameraSize and...

... Made it a run-time set. Also added some dummy UI/Sprite objects to
test with.
Bugfixing - Round 2...

Fixed an idiotic SpriteCenter mistake, got rid of the nonsensical origin
define for all sprite/UI classes, made it a bool toggle if at some point
I need default upper-left origin. Additionally added some comments.
Commit weirdness...