Remove usage of ng-include and template from mct-include for
compatibility with element-level transclusion. Has useful
side effect of pre-fetching templates and reducing watch
count.
...to add/remove conditionally depending on the existence of
certain templates.
Note that this currently breaks mct-include due to an incompatibility
between element transclusion and directive templates; see
https://github.com/angular/angular.js/issues/3368.
...from mct-include. Improves behavior of that directive and supports
testing of changes to remove whole elements when inapplicable,
nasa/openmctweb#195.
Trust resource URLs to skip SCE-checking (which profiling
flags as a performance problem) for mct-include and
mct-representation; these URLs are pulled from bundles and
not user-entered, so should be trusted. WTD-1256.
Support priority ordering from the mct-include directive
(such that the highest-priority template for a given key
is what gets included.) Needed to support variations among
application logos in the bottom right (depending on deployment.)
WTD-667.
