Add ApplicationTransactions/CustomField based user profile editor

Summary:
Adds a profile edit controller (with just one field and on links to it) that uses ApplicationTransactions and CustomField.

{F45617}

My plan is to move the other profile fields to this interface and get rid of Settings -> Profile. Basically, these will be "settings":

  - Sex
  - Language
  - Timezone

These will be "profile":

  - Real Name
  - Title
  - Blurb
  - Profile Image (but I'm going to put this on a separate UI)
  - Other custom fields

Test Plan: Edited my realname using the new interface.

Reviewers: chad, seporaitis

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D6152