[#781] Begin improving IFacets docs

Better docstrings and an example extension for IFacets. Both still need
some work..
[#1594] Fix breakage in package groups page

The group.type field, when undefined and merged with a unicode string
returns a unicode, which causes a traceback thanks to `url_for` in
pylons not accepting unicode.
Move the closing div inside the block

Fixes #1619. Move the closing div inside the block since it's defined
in the block anyway.
Merge branch 'master' of github.com:ckan/ckan into 781-improve-ifacets-docs

Conflicts:
	setup.py
[#781] Finish the IFacets docstrings
[#781] Remove the example IFacets plugin

It has no tests, and I'm not going to write any for it right now.
Merge branch '1619-template-block'
[#781] Add small comment about ordering
Merge branch '781-improve-ifacets-docs'
Merge branch '1594-package-group'