BUGFIX: based on dropdown was not being generated by PhaseController. Fixed.
Added some docs
1. Extracted the use of Gtk.TreeModel's completely from the model part of the code.
Models now use regular lists that are wrapped by an ObsWrapper subclass to allow notification of changes.
Adapted the controllers to work with this new approach. They wrap the lists in an actual ObjectListStore for use in the Gtk view.
2. Merged the pyxrd and gtkmvc frameworks further together.
3. Moved model meta-data to an inner Meta class
4. Bugfixes in some views
5. Tons of small changes to make things work the way their intended + new UnitTests