Allow dealers to buy sponsorships while applying

Adds the badge choices back into the dealer application, and makes them
work for new dealers.
Add admin_table_opts

Although dealers can only select 0.5 through 4 tables, admins need to
include more. Added a new set of options for the admin form.
Merge pull request #852 from magfest/fix_dealer_reg

Finalize dealer registration
Add background to dealer pages

Adds the masthead and white background to the dealer confirmation and
group member pages.
Refactor Javascript into specific files

Moves the javascript for pre-registration pages into just the pages that
will need it.
CONTACT_URL fix for *.py
Update group_members text

Updates the text to match AC dealer registration needs. Also adds a
background to group_extra_payment_form.
Show correct badge type when claiming badges

When claiming an unassigned badge in a group, the attendee object has no
useful information. This goes off the group object instead so it
displays correctly.
Show correct prices when claiming badges

Because attendees claiming badges in a group are new, their badge price
was erroneously displayed as the Attendee badge price. This
special-cases that down to 0.
Merge pull request #854 from magfest/fix_dealer_reg

Fix group badge claiming and display fixes for dealers
Merge pull request #853 from magfest/CONTACT_URL-fix-for--.py

CONTACT_URL fix for *.py
Typo fix

Fixes a typo in one of the validation messages, and centers the "dealer
application" heading.
Merge pull request #855 from magfest/fix_dealer_reg

Typo fix
Merge pull request #66 from magfest/ac-staging

Kitsuta's Dealer fixes