Merge pull request #212 from spring-peepers-2014/technical-debt-begone

Add SidebarView
- Removes duplicate methods from SessionsView and FavoritesView
Refactor js add artist to favorites menu

- Remove FavoritesView.append_draw method
- Sidebarview.add now responsible for rendering new favorite
- Update method calls in FavoritesController
Remove FavoritesView

- All FavoritesController view methods in SidebarView and BandView
- Delete FavoritesView
- Remove FavoritesView initialization from ApplicationController
Add if statement to signupLink Listener

- signupLink is not in dom when user is logged in