Miscellaneous text changes

Changes several messages to better match AC's needs. Also changes the
text on the form page to only link to dealer registration when it's
public, not when it's enabled. Uses new DEALER_REG_PUBLIC config.
Fix dealer ribbons and send payment notification

Fixes ribbons so they work more consistently. Also adds an automated
email that goes out to the Marketplace head when an approved dealer has
paid for their registration.
Fix badge printed name for dealers

Allows dealers to enter a custom name for their badge.
Fix dealer validation

Checks specific to dealers were not being run. To be perfectly honest, I
don't exactly know why this fixes it, but there you go.
Changes web address to tax id on admin form

A simple text change that I overlooked, telling admins that the website
column is the tax ID.
Fix badges dropdown on group admin page

The badges dropdown on the group admin page used badges_purchased, but
the logic of the code for the groups form treated it as the total number
of badges. That meant you would have cases where if you simply tried to
save a group's info, it would actually try to reduce the number of
badges in the group. This fixes that, and adds a badges_purchased count
next to the dropdown.
Improve table_opts names

Changes the table_opts code to add prices dynamically, so they aren't
being enumerated twice.
Merge pull request #849 from magfest/fix_dealer_reg

Fix dealer registration