Python 2to3 entire codebase

Entire codebase (including plugins) converted to Python 3 support using
2to3. This should now work fine on Python 3 (and therefore Linux).

Once tested on Python 3/Linux merge to mainline.

Pathomx is now invoked from the command line with:

python -m pathomx.Pathomx

...from the parent folder. This is because it's now a package, and using
relative imports.
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes - alternate approach to the UnicodeCSVReader
Python3 fixes - alternate approach to the UnicodeCSVReader
Python3 fixes - alternate approach to the UnicodeCSVReader
Python3 fixes - alternate approach to the UnicodeCSVReader
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes
Python3 fixes