Adjust the default Arena Trip Registration Module in the following ways:

1. uses a more selective process for adding mission team members than just paying your deposit
2. WVC employs an escrow account for trip members who are contributing their own money. In the event that they are able to raise all of their support any amount they have contributed is refunded to them
3. WVC doesn't call trip goers Attendees they call them Team Members
4. Removes the multiple contribution values and employs a single editable contribution field
5. Only two actions: support the team in general, or validate a team member and apply support for them