Setup.py: Port to python3 and enable 2to3 support
Run examples through 2to3
REF: import Image -> from PIL import Image
Py3: Change types.IntType -> int ...
Py3: Migrate cntr.c to be python3 compatible.
Merge branch 'master' of https://github.com/enthought/chaco into python3
Minor py3 compat and other fixes
TEST: Make test python3 compatible and use descriptive asserts.
Merge branch 'master' into python3

Conflicts:
	chaco/scales/scales_test_case.py
Merge branch 'python3' of github.com:pankajp/chaco into 0.5.0-dev