Merge branch 'master' of git://github.com/melinath/philo

* 'master' of git://github.com/melinath/philo:
  Implemented the solution proposed to #130 - removed TreeModel and made a SlugTreeEntity subclass of TreeEntity to handle Node and Template. Correctly subclassed SlugTreeEntity.Meta so that Node and Template actually have the unique constraints they are meant to. Minor correction to TreeEntity.get_path.
  Minor corrections to TagCreation.js. Resolves issue #125.
  Switched contentlets to use lists rather than sets to preserve ordering. Resolves issue #132. Added some basic tests for containers. Moved build_extension_tree out of Template.containers.
  Minor correction to FeedView docstrings. Resolves issue #139.
  Refactored RequestNodeMiddleware to use SimpleLazyObject - comparable to django r16297/r16305. Resolves issue #144.
  Corrected philo tests and removed all use of penfield models in those tests - resolves issue #80. Minor correction to TreeModel.get_path to save a query.
  Added a 'getting started' tutorial and a short intro to philo page to the docs. Improved Attribute docstring.