Made PEP-8 compliant

Removed multiple imports in one line, 2 blank lines between function
declarations, splitted >80 chars line. Verified with pep8 checker
https://github.com/jcrocholl/pep8/
Made directory an mandatory argument

And not a mandatory "option"
Rationale:
http://docs.python.org/2.6/library/optparse.html#what-are-positional-arguments-for
Added a --count option as a useful simulation

-c Run over the directories and count the number of files without
idv2 tags in them. Do not change them
Use Popen() to supress stderr. Also, no grep

No shellquoting needed with subprocess
Removed bogus and unneded \

As per the Dictator's wishes
Merge pull request #1 from odkq/master

Hereby I submit some improvements to your most fine and convenient tool