WIP
Stop showing "Add a new proposal" button when it's time

The code would already prevent you from actually submitting a
proposal if no proposal sections were open. This change stops
displaying the button.
Start on review side of finaid
Set open period for financial aid applications in the database

Instead of a setting, control the open period for financial aid
applications using the database.

This is mainly because we want to be able to enable applications
on staging for testing without enabling them in production, though
it also means pycon organizers can control the period more easily.
Financial aid application cleanup

* Add hotel arrival and departure dates
* Put verbose names on every field (for translation)
* Style the button for submitting an application message correctly
* Update the tests
Fix hotel dates

* Hide hotel dates unless hotel grant is checked
* Give hotel dates default values so that the form will be valid
  if someone never checks hotel grant
Merge branch 'feature/finaid-application-cleanup' into develop
Start on translation

* Add fab commands to update message files
* Go through, marking English text for translation in Python and
  templates.
Financial aid review team

Implement the review team:
* new permission in fixtures
* new team in fixtures
* implemented is_reviewer() code

Also switched to using natural keys in the permissions fixture, which
we should have been doing all along.
Escape messages; add form error message

* When displaying financial aid application messages, escape the text
  for security.
* If there's an error on the financial aid application form, display a
  message at the top so it's more obvious.
Merge branch 'develop' into feature/141-finaid-review-app
Merge branch 'feature/review-finaid' into feature/141-finaid-review-app

Conflicts:
	pycon/templates/finaid/application_list.html
Merge branch 'feature/finaid-review-team' into feature/141-finaid-review-app
Commit the migrations to get them out of the way
First pass at the reviewer's app
Load jquery on registration page

We inadvertantly removed it and it is needed.
Add test that user cannot see private messages about their application
Make vendor URL configurable, add docs, add CSRF token
FOO
ADD migrations