Remove dj-user-accounts

That's a nice macro, but we don't need it.
dj-user-accounts stands in the way of using more generic AUTN_METHODS

Assorted fixes (#47)

* Invokes the site tree fix from previous fixes.

* Adds a disclaimer noting that previous years’ accounts have not been carried over.

Fixes #43

* Adds proposal type to the proposal summary page.

Fixes #40

* Adds travel/accommodation assistance to the proposals page, but makes it only visible to speakers in the proposal, or review managers.

Fixes #41.
Fixes #42.

* Reduces a lot of the whitespace in the header and footer.

Fixes #44

* Proposals review page now shows information for every speaker on a proposal.

Fixes #45

* Makes sure that non_field_errors are displayed by forms.

Fixes #37

More dashboard and settings themes (#29)

* Proposals forms now have a header panel

* Adds panels to the speaker forms

* Imports latest pinax accounts templates

* speakers/base and proposals/base now derive from utility_page.html

* Most login forms now derive from take flight themes

* Missed email_confirm

* More accounts bits

* Restructures login form

* Puts submit etc buttons inside fieldset borders