Change names of featured items

These are unfortunately hard-coded right now, so they've been changed to
match AC requirements.
Change descriptions in pre-reg form

Changes the badge descriptions to reflect Anthrocon's actual badges.
Adds a detailed explanation about dealer registration.
Hide kick-in level boxes

Anthrocon attendees won't understand kick-in levels, so this hides the
dropdown to make it look like they're choosing a badge type.
Pass amount paid to the confirmation page

Passes the amount an attendee was charged to the paid_preregistrations
page, if it's available, so they can see a confirmation of what they
paid.
Merge pull request #687 from magfest/text_changes

Text changes