Basic configuration for flake8

flake8 is a wrapper around pep8 and pylint and helps keep a good code
hygiene.  The setup just ignore /lib/ which is made of third parties
libraries.
Code hygiene

Fix a bunch of issues reported by flake8, a pep8/pylint wrapper.

E101 indentation contains mixed spaces and tabs
W291 trailing whitespace
W292 no newline at end of file
W293 blank line contains whitespace
E301 expected 1 blank line, found 0
E302 expected 2 blank lines, found 1
E303 too many blank lines (X)
W391 blank line at end of file
Code hygiene for comments

Fix comment related issues reported by pep8:

E261 at least two spaces before inline comment
E262 inline comment should start with '# '
Merge pull request #3 from hashar/pep8-hygiene

Pep8 hygiene