Use button styles more consistently.
Fix tests.

* Insert date as text now that deploy_at uses datepicker.
* Deal with case when user is not logged in.
Use Bootstrap styles on activity list.

Remove specific overrides.
Tweak application table styles.

* Add header style, align sorting arrows in centre.
* More spacing: remove table-condensed style, split deployment details to move
  date/time to next line.
* Use 'plus' glyphicon for 'add deployment'.