Update readme and fix some bugs

* Docs: copied the doc from __init__.py to README.rst
* Cleanup: got rid of some unnecessary build files for docs
* Bumped version number to 0.11
* Cleanup: cleaned up some imports
* Added: started allowing unicode strings to be in a unique index
* Fixed: objects modified after session.commit() are now added back to the
  session
* Fixed: incorrect error when an object is re-added to a session
* Fixed: error when a non-required ManyToOne relationship value is not
  present on load
* Changed: lists provided to .filter() method on query objects are now OR
  queries. To use AND queries, make multiple .filter() calls.
* Added: .all() and .first() methods on query objects
* Added: alternate .save() method on the session that you can pass entites
  to in order to save all of them
* Added: util.refresh_indices() function to refresh all of the index entries
  for all of your entites of a given model.