Remove all the unused Jinja blocks from layout.html. Also remove some unused HTML elements and fix whitespace.
testing.TestCase is abstract; it won't work unless _config_dir_path is filled out.
Autofocus the query field at the root of each tree (only). Fix bug 973588. Close #245.

Add an instance for testing markup generation.
Add a regexp example that uses quotes.

jcranmer thought we had taken quoting away altogether when the old slashes didn't work.