Updates to `.gitignore`
Readme - bump copyright date, Readme updates, fix package name, simplify install instructions, add neglected third settings parameter.
Drop Lettuce tests
Tests - cleanup imports
Tests - use `self.settings` to be more Django-like (`ArmSectionsTestCase` backported it from Django 1.4)
Tests - user `override_settings` instead to avoid so much indentation. PEP8
Tests - PEP8; use more appropriate `asserts`
Remove incorrect namespacing.
Documentation - remove Sphinx docs and update Readme.

The Sphinx docs are out of date, a maintenance headache and Armstrong just isn't using them.
The Readme gets new content and uses the new "contributing" section text.
PEP8 reformatting
Fix and properly deprecate the older ItemFilter `find_related_models` method.

The way it was coded with the `ItemFilter()` instantiation would never have worked. The setting is supposed to be a class which `get_backend()` instantiates.