Updated lalapps python syntax for python3

This merge updates the python syntax for all python code in lalapps, specifically for except and print usage:

• 5eb4963e: 2to3 --fix raise --write lalapps
• 6a191e22: 2to3 --fix print --write lalapps

None of the modified code has been tested in any way.

All changes are designed to be backwards compatible with python 2.