Made a few minor changes to allow lcov_cobertura.py to be run as a console script.

[aglosband]

For my use case, it makes things easier if I can run lcov_cobertura.py as a console script after installing with pip install: http://python-packaging.readthedocs.org/en/latest/command-line-scripts.html#the-console-scripts-entry-point. I figured other people might want to do this as well. I couldn't think of a way to write a unit test for this but I added an example to the Readme.

[eriwen]

Thanks, Alex! This looks good.