Fixed a bug that was killing single-quotes

Specifically, if you had an apostrophe in a Text Property (not a Large
Text), when you went to display that in the Editor or _edit, the field
would get cut off at the apostrophe, because we were generating illegal
HTML.

Along the way, introduced QLog, so that I could have QLog.spewThing()
for debugging.
Fixed reifying a Tag (by going to it and editing it)

Previously, when you went to edit a Tag, the initial Display Text was
always the system default.  Changed to use the Space's current Show
Unknown Name text, which is actually the right value.

Also fixed Show Unknown Name to be a Large Text instead of a QLType --
not sure why I had it that way, but it was clearly incorrect.
Things now have a small link to their Models

It's a little feature, but one I keep finding I want.
Don't let folks edit non-local Things yet

For the time being, we're just disabling it in the Editor.  In the
medium term, this will get complex.