Merging in many changes from temp branch

My local repo got corrupted, so wound up on a branch for a week.  Have
had no luck restoring the master branch, so re-cloned from GitHub, and
am merging everything in.

Major change is that the new Add Property / Create Property workflow now
works nicely: you can now add or create properties while you're building
Things, which makes it all work much more smoothly.  Many, many changes
caused by this.

New "API" flag in create/edit forms, for AJAX use, which returns
different values.  doCreateThing can now be called from AJAX.

Finally replaced jQuery UI buttons with Bootstrap ones.  Along the way,
switched to using the Bootstrap/Glyphicon icon set.

Introduced the Property Summary / Property Details properties, so that
all the props are properly documented.

Property names in the Editor now show their Summary as a tooltip.

The Trash and Revert buttons now have distinct icons.  (They always
should have had.)

Renamed most of the Types -- the old names have bothered me for ages.

The Trash button now takes effect immediately, without requiring a
roundtrip.

The requiredCollection option on PType is now respected, if provided.
So the UI forces Tag Sets to be Sets.

The index page and toolbar use Aaron's new logos.

Removed Chosen, given its poor interaction with Bootstrap.

We now are better about putting all the right hooks onto newly-added
Properties.
Release 0.3.18