Show current user in footnotes
Merge pull request #86 from sarahsemark/current-user-in-footnotes

Thumbs-up for usefulness!
Make Postings belong to User, fix #46
Include and set a default sort order
Associate models with users and check for auth

Check for login on all auth-required pages and redirect if the user isn't
signed in. Extra Pundit check for scopes/authorization on virtually every
DB call. So things are getting there re: security.

 * Fix #84
 * Fix #87
Ensure user objects exist.
Set up very barebones placeholder dashboard and show as root to logged-in users.
Create route for dashboard and link-up/show as root to logged-in users.
Clean up welcome message and log out button.
Pretty up elements a smidge.
Show upcoming interviews.
List jobs that need an application, and number of follow-ups required.
Add some preliminary prettiness to dashboard action-panels.
Pretty up the upcoming interviews panel in dashboard with icons.
Add a (placeholder) progress bar.
Add placeholder for statistics panel.
(Math is hard.)
Streamline li elements.
Whoops.
Pretty up statistics panel.
Add number of jobs applied to this week.