Add search

[jeff-r]

We need to be able to search for organizations and locations within the admin site.

[kelfink]

I have pushed a branch which allows simple 'like' search for both the admin/locations and admin/organizations pages. I had to change the way policies work, to return a more consistent active relation. Not all the tests pass on my machine, but the failing ones are, I believe, due to some necessary step in setting up seed data, plus some changes in our repo's master branch which change the way beginning and trailing whitespace is handled when adding records.