Hide "Application Action Title" field on board page

This is already rendered as part of the button, so it shouldn't
be shown in the list of fields.

Addresses #3551
Custom 404 and 403 pages

This is mostly to make sure the nav menus show up on the 404
page.

Addresses #3551
Use Table-Cell technique to vertically center city names

Use this tecnique because it works for variable height elements,
in our case city names that might span multiple lines, and
works in IE8.

Drupal already gives us enough container elements to do this.

See
http://coding.smashingmagazine.com/2013/08/09/absolute-horizontal-vertical-centering-css/#Table-Cell

Addresses #3551