Add rdio integration, user and song models, and stub out graph

- Graph stubbed out from Google Graphs
- Document ready removed from most page javascripts
- Rdio integrated (tested for logged in rdio users)
- Table for songs lightened for readability
- Visualization page stubbed out
- Model and migrations for user and song models added
Merge branch 'jlt-rdio-integration'

* jlt-rdio-integration:
  Add rdio integration, user and song models, and stub out graph