Prevent pagetree's jQuery from interfering with the main app's copy

Even though pagetree and my django app (worth2) are using the same
version of jQuery, since worth2 is using requirejs it was causing
jquery-ui to not get loaded correctly, breaking the pagetree admin
interface.

This commit loads jQuery in a more cautious way that prevents
interference, in the same way that django-debug-toolbar does it:
    https://github.com/django-debug-toolbar/django-debug-toolbar/blob/69bf1eb127f8c1b6b7c6c2e798ccd208293c1309/debug_toolbar/templates/debug_toolbar/base.html#L7

Also:
- Update jquery-ui to 1.11.2
Merge pull request #14 from nikolas/master

Prevent pagetree's jQuery from interfering with the main app's copy. okay - this is fine.
Add csrf_token to pagetree admin forms

The csrf_token template tag was only present on one of the forms here..
since ccnmtldjango has csrf checking on by default, I think we include
the csrf_tokens here.

I tested the csrf_token templatetag when the CsrfViewMiddleware is
disabled, and the forms still work.. so if you need to turn it off for
some reason it won't require a change to pagetree.