PEP8 mass fixes

With the help of the PEP8 script, a semi-automated clean
of the code base was made, and effectively changing some
of the coding style rules of our code base:

 * No more 2 lines spacing among functions
 * No more combined module imports

In the end, it was going to be too difficult to take
into consideration E501 (line length > 80) errors and
W601 (.has_key() is deprecated), so these were ignored,
at least for now.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>