Inline entity tiles

Inline Entity Tiles allow the engine to define a detail screen for a datum that is available persistently after the datum is selected. Additionally, the element can contain its own expanded detail set on-demand, allowing clinical and complex interfaces to more rapidly transition between selecting and interacting with a model.

X-Requested w/commcare-odk and commcare.
hm... I can check that out. This fixed a bug where the title was being set to "" or null or something, but I should really fix that bug, not workaround it.