Create a SessionContext model.

* Get rid of context that is stored in network.js and user.js, which ended up causing aliasing problems.
Split context into network-context and user-context
Issue 3867: Change footer icon which is blurry and cropped
Change the source png of the footer image in dialog
Declare provisioning and authentication urls
Simple prov and auth without reusing existing resources. Works with Desktop
Reusing CSS and HTML from dialog.ejs
Show error message on failed auth
Match Persona's disable email field code
Got ordering of scripts right. Extract idp_authentication.js
Incremental progress, add new user flow
Make wsapi/address_info provie auth and prov info
Created a Discovery web service for Desktop
A couple gross hacks to get around bugs.
Minor cleanup
Tighten up authentication for new, registering users
jshint and travis - haters gonna hate
well known now returns auth and prov urls in well known
Use cachify for idp_authentication resources
cleanup - pass in email to authenticate module