Finish up P2P MVP

[solebared]

When P2P mode is enabled:

• Contribution button on NavBar should be accessible w/o login
• Respond buttons on /contributions should only be visible to admins (Hide the "respond" UI items when not logged in #824)
• Fix bug with ClaimContribution interactor missing params (Fix missing params error when claiming #832)
• Check if claiming sends an email
• Remove person name in map view Remove name in map view #847
• Re-enable registration Re-enable registration #840
• Make email required on ask/offer forms (until sms is ready)
• Prevent claiming email-less contribution. Prevent p2p user from claiming a contribution that does not have an email. #831
• Redesign From section of Claim form, drop ability to override email, add disclaimer text no how to change your account email if you don't want others to see it. Don't allow email override when claiming a contribution #855
• View button on List view and Map view

Nice to have:

• Implement description from Expandable options on Ask/Offer form #310.
• Add note in ContactMethods re looking up fontawesome icons

And then:

• Cut a release!

[solebared]

Done! w00t!