[ITK Community] Support for different python versions

[Michka Popoff]

Hi

I am currently cleaning up the python code in ITK (pep8 cleanup and removing some old deprecated stuff).
I wanted to know what versions of python would we like to support? I found some compatibility code going back to python 2.3.

My proposition is to support 2.7.x and 2.6.x officially, which should not be too difficult.

I will possibly look for python 3 compatibility in the next months, as swig seems to support python 3. (I hope this is feasible without too much pain)
If anyone has some knowledge about maintaining code with python 2/3 compatibility, any piece of advice is welcome.

Any thoughts on this?