[PEP8] Substitute `###` with `#` in the notice

The 'tripple' commentts are against PEP8 coding style. So it would be
better to use simple comments there. Doesn't change the visibility, but
helps when checking code for syntax errors with checkers like pylint.
Update .gitignore

Ignore pyreverse files and vim swap files.
Move change_prefs_for_validity into another file

By doing this, we can avoid a circular dependency, which might be a
problem in some case.
Do multiplication to avoid code errors

To expose 1024 multiplication in the code is slightly more verbose.
This should not cause any major overhead, but if it does, we could
check.

On the other hand something like `1 << 10` for 2**10 could be also used.
Fixup to the print_function from __future__
Put global vars from rpdfile to config

We avoid circular dependencies and sometimes the imports become much
simpler.
Lots of PEP8 fixes on syntax

This should include only syntax changes (like white space management and
similar). The program still runs and everything should be good. I did
not split the commits, because it is basically the same type of changes
over the whole codebase.
Add the ValidatedEntry class back into imports

Signed-off-by: Ignas Anikevicius (gns_ank) <anikevicius@gmail.com>