Support Python 3 using 2to3

[puzzlet]

But this won't run in Python older than 2.3, in theory.

[meshy]

👍

[mgedmin]

Please don't use 2to3. Many projects started on that road and ended up regretting it.

It's not that hard to have a single codebase that supports Python 2 and Python 3. http://python3porting.com/ has good advice.

[meshy]

I agree, having now converted a couple of bits and bobs myself. This post is a great help :).