preserve 3d camera aspect ratio on window resize
TODO: find out about the TrackballControls which is present in Three.js
but not in three.js and seems to not behave consistently
(cherry picked from commit 48b5f3dbc8027e69075eab3d61dfd0d9668c428a)
Merge branch 'master' of github.com:acardona/CATMAID

Conflicts:
	django/applications/catmaid/static/webglapp.js