Fix a small formatting inconsistency (four spaces instead of two).
Fix too-broad except clause.

This is Python best-practice. It's important not to catch things like
KeyboardInterrupt (Ctrl-C).
Use a more Pythonic tuple-based version number comparison.

These are functionally equivalent.
Update error strings to reflect support for requests and the fact that it's the prefered HTTP library. Fixes #16.
Remove some unused variable assignments.
Merge pull request #31 from fletom/master

Some minor fixes and improvements.