Add custom z-index for widgets after jquery has been loaded

Move Leaflet apps widgets at the very very top (above the header and footer).

The CSS rule is inline in the template HTML so it will always parsed _after_ jquery.

![screenshot from 2014-11-03 11 42 07](https://cloud.githubusercontent.com/assets/1818657/4881202/19133064-6346-11e4-889a-3389e1a52a70.png)

Probably is better add a note in our css file a note that point to this file to avoid headaches in the future to find where this z-index is set.