util/construct module, test, and doc
Controller and Entity controller cleanup

Pulled the more Controller-universal functions out of Entity. Namely the
methods involving the mechanisms behind swapping views. Those functions
were then refactored to use util/construct module to make more generic
usecases.

Entity view was also refactored not to depend on Model class as the sole
provider of a Model. There's no more hard instanceof checks inside View
Entity. That way, both Model and Entity View become generic enough to be
used as defaults for Entity controller.

Lastly, the old Controller static methods were simply removed because
all they did was do some very application specific things in order to
AJAX GET a jQuery.tmpl template and inject it on the page with a
<script> tag. They should instead be app-specific traits.