Implemented active jQuery sticky footer

@wescott 

This code calculates height of window, content, footer and the footer offset.

On load it then figures out if the footer height + footer offset is smaller than the window height. If that is the case it increases the size of the content div to stick the footer to the bottom of the window.

It also recalculates and resizes content on page resize.

If on page resize you make the window smaller than the original height of things it reverts the content size...