jQuery.footHovzer: Fix scrolling issues

jQuery.footHovzer: Fix scrolling issues

Fix scrollbar appearing if the page does not fill the screen, and the
debug toolbar is enabled.

This patch also fixes an issue where the page will have a height of
~1000px if the CSS is loaded after the JS executes (display:none
isn't triggered before the outerHeight() calculation). I've only been
able to fix this by adding a setTimeout, which is a little bit hacky..
but can't figure out how to solve it any other way.

Bug: T38273
Change-Id: I1f92cb0681b7a82a5936267c120f85481a95a962