[#1512] Fix select2 files on 2.2.1

Due to cheery-picking #1512 commits without merging #1278 first, the
source files for select2 where incorrect on the 2.2.1 branch (js error
on /dataset/new when running on debug mode). select2 files are now in
sync with master.
[#1791] Keep filters when ordering dataset listings

There is a `form.hidden_from_list` macro call in the
`search_form.html` snippet that did not get the `fields` variable it needed
to create the necessary hidden inputs.
[#1767] Fix bug with send_email_notifications not working with paster

The problem is that our validators notice that .send_email_notifications()
didn't call its auth functions and raise an Exception. But it shouldn't call
it's auth functions when being called with paster anyway, so it's correct.

This fixes that.
Use assert_raises instead of the full nose.tools.assert_raises