Jstree

====
* Add Python 3 support.

====
* Removed the 'id' tag from general data.
* Renamed 'metadata' to 'li_attr'.

====
* Enhanced JSTree so it can add IDs to leaf nodes for selection in
a jsTree. Although, this may need more work after testing in
a jsTree application.
* Updated all the doctests to handle the additional burden
of users being able to pass in arbitrary attributes and
"path object ids".
* Removed ability to copy JSTrees directly in __init__ since it's
not actually a use-case right now. Trying to avoid code smells.

====
* Started updating the changelog, finally.
* Simplified the tree data structure by removing the insertion of
"data" at the top-level. This means JS clients will have to add
it themselves when doing full-loads of data off the server, but
it also means that AJAX-based jsTrees should work properly. More
testing on this is required, however.
* Started enhancing the in-code documentation so devs get a better
sense of how to use the code.
* Hardened jstree.Node to be "as immutable as possible" right now
without a lot of major code changes.
* Enhanced jstree.Node for advanced usage. Users can now pass
additional attributes directly into it if they're managing
a set of Nodes themselves.

======
* Fixed 'dictobj' as a requirement of jstree.

======
* Changed dev status to alpha. Was incorrectly set to beta.
* Fixed setup.py for users of Python pre-2.7.
* Added Node class to make creation of JSON more manageable.