static/css:

Removed some unneeded styling from the footer in both leaflet
and extjs css.

The base oqplatform.css file takes care of this styling.
templates/leaflet_base.html:

Cleaned up css and javascript includes.
templates/oq_base.html:

Changed singleton div class names to ids. This makes more sense for
styling and other behavior.
templates/oq_base.html:

Added context ribbon, which is displayed on leaflet-based map pages
to hold context-senstive controls/buttons/links/images, etc.
templates/leaflet_base.html:

A minor adjustment to map placement.
static/js/base_leaflet_app.js:

Take into account also the context ribbon height when reszing a
leaflet map. This way, we can always ensure that everything fits on a
single page.
static/css/oqplatform.css:

Removed some unnecessary/bogus styling.
static/css/oqplatform.css:

Updated class references to id references, since these elements are
now considered singletons.
static/css:

A bunch of tweaks to do the following:

    - Center the index page content, and make it scale well as the
      window is resized.
    - Center and fit leaflet maps properly and consume all available
      space on the page.
    - Integrate the context ribbon in leaflet pages.