Add season_badge_price property

This is for displaying the correct price on badge_choice.html
Adds Season Pass option

Sends through the season pass price if checked - works pretty much exactly like supporter badge option.
Updated text for supporter passes

Supporter passes are no longer new so I changed the wording a bit. Also added MAGFest 8.5 to the list of events.
Create season_badge_description.html

This is for badge_choice.html to display the features of the new season pass option.
Create attendee_badge_description.html
Update season_badge_description.html

Taking out the UL list elements because I'm leaving them in the badge_choice page after all.
Update supporter_badge_description.html

Putting list elements inside this page so all badge descriptions support multiple items easier
Create group_badge_description.html
Update attendee_badge_description.html
Update attendee_badge_description.html
Update supporter_badge_description.html
Update season_badge_description.html
Update supporter_badge_description.html

Fixing indent. Yes, really.
Split out attendee and group badge descriptions

For consistency's sake, I'm making some updates to the badge descriptions.

First of all, I'm taking the UL and LI elements out of this page, because it makes no sense to not have those inside the included pages.

I'm also taking attendee and group badge descriptions and putting them in attende_badge_description.html and group_badge_description.html to match supporter and season supporter badges.
Price_change check

Changes the group_price_notice warning to only display if PRICE_CHANGE is true.
Update attendee_badge_description.html

Changing PRICE_CHANGE to match the variable name's change to PRICE_BUMPS_ENABLED
Update group_badge_description.html

Changing PRICE_CHANGE to PRICE_BUMPS_ENABLED
Add new price notices

Adds the new "price will update blah blah blah" notices for supporter and season supporter badges. Changes the Notice class so it'll take and use an amount_extra argument to pass kick-in levels.
Check for price bump and display warning text
Check for price bump and display warning text