Bootstrap-ify the task listing

Add Bootstrap CSS and divs to the task list form for consistency.
Point Login link to correct URL. Fix </ul> bug.

Was missing a </ul> closing tag.  Also needed to point to the
correct login URL (which may be temporary until Backbone takes
control of the login flow)
Add MyUSA (my.usa.gov) Authentication Support

Implement the MyUSA strategy for passport, and add an option to
login using MyUSA.