Move todo list into its own tab

Refactor templating into todos-partial.html
Add Note type & db handling for it
Rename todoId to objectId so that we can use the same type for notes
Re-indent todos-partial template
Add note creation and editing

- Add REST handlers for notes
- Hook things up in JS

Note separate GET handlers for /api/note - one for querying a single
note and another for returning a full list of them.  These correspond
to AngularJS's $resource.get and $resource.query default behavior.