Section to control mappings plus model simplifications and live binding tightening-up

Major contributions in this commit: - section/control mapping dialog checkboxes all work (N/A will work when merged with Dan's AJAX prefilter changes) - Cacheable Model code has been tightened up with attributes/serialize declarative patterns, the addition of the stub() function to return just ID and HREF, and updates to models/model functions to ensure that sub-collections never lose sync with active observes bound to views. - Tree view updates showing the controls correctly on show, live binding on tree keeps up with mapping. - ControlSection model in section.js gives an example for how to create/destroy relationship objects.