Various fixes 2

This branch fixes/updates lots of little things.

The last two commits are a bit debatable maybe, choose them if you like.

3995178 just avoids warnings, but requires changes in the user code

ba619c8 fixes issue #65, but contradicts the JS original (although THREE.js has also gone in this direction in later revisions: https://github.com/mrdoob/three.js/wiki/Migration#r52--r53)