Add a utility function to get template data for the POCs to which a user is actively registered
add tests for the new utility
Implement mechanism for switching POC and MOOC views

Ensure there is a consistent key for the session dict that will store the value of the poc_id if one is active.  If none is active, the mooc is assumed to be active.
Add mooc_name, mooc_url and active to the dict for each poc membership.

Update the navigation template to show link to mooc if poc is active, or to poc if not.