Merge pull request #42 from pretenders/alex/326-github-oauth

Alex/326 github oauth
Add provider resource and controller, plus backend
Restyling based on sidebars for menu and submenu
Ensure vertical scrolling applies to main content only
Font and icon styling
Routing and controller work for providers
Better isolate styles for marketing and logged-in pages
Use specific icon as separate setting
Initial client for Target Process
Sidebar adjustments
Main menu as a directive
Directives for inner menus
Progressively revealing items in sidebar
Merge pull request #44 from pretenders/carles/273-available-providers

Carles/273 available providers
Github: Log non 200 responses in key exchange
Save github access token.
Ensure no multiple OAuth tokens are created per user/provider