Nuance - get some scaffolding up there

Summary:
I updated the wiki too - https://secure.phabricator.com/w/projects/pebkac/ - with what I am thinking right now. Rough plan here is

• next diff:
  • implement editors and transactions
  • implement "web type" for contact source
    • /pebkac/item/new/ will be the entry point for this
  • implement "actions" on a contact
  • probably some "polish" on the scaffolding laid out here; like "create" permissions maybs
• diffs after that:
  • implement "twitter" type for source
  • implement email reply handler stuff for item and source

Probs a great time to blast huge holes in all this stuff. :D

Test Plan: these pages load and arc lint doesn't complain

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran, chad

Differential Revision: https://secure.phabricator.com/D7465