Pep8 compliance

[vanadium23]

So I've done basic integration for pyflake8 (#102) and found 400+ errors: some just skipped (e.g.: error for using lambda instead of def), but some was useful.

For example: F821 tells on py35 about unicode undefined world, but in py27 doesn't. May be revert it and fix those problem?

[gi0baro]

Ok, thank you! But I'm gonna ask you some changes in order to merge this:

• ignore pep8 E265. This won't make the code less readable, since the majority of comments in weppy start with "#:" which is my notation to briefly describe the next block. Moreover I see some false positives like in https://github.com/gi0baro/weppy/pull/103/files#diff-4cdf38a9a4e12e67ab1d0f25c7b5157eL16 and generally in all the regex rules
• watch out carefully where you apply E711/E712, since in all ORM queries you can't use db(Model.field is None) but the wrong pep notation db(Model.field == None) or the query cannot be built.

Also, If you don't mind, rebase your branch into a single commit so we can have a better commit log :)

[vanadium23]

• About E265: may be we can still use '# :' with space instead of '#:'? Or may be better replacement like '# *'.
• Can you provide code example why it has behavior like this? It is only semantic difference, when you eq None it force to check for identity, because None is singleton in Python. And to show difference better to use is.

query = 0
query = query == None // False

query = 0
query = query is None // Also False

Ok, I'll rebase after clearing this questions (:

[gi0baro]

• I think it would be best to just ignore E265 at the moment, then I will figure out a decent way to replace my comments
• It's not just semantic, since you can override the built-in methods for equality comparison, but not for identity comparison; since weppy uses those methods to build queries from ORM objects it's the only way to operate. In weppy when you want to query for data with NULL values, you have to write db.where(Model.field == None).select() since I can't override Python behaviour to write db.where(Model.field is None).select(). Model.field == None builds an SQL string, not just a boolean ;)