Added new spinner for ajax loads
App is now only 100% height when sidebar or map is displayed

Allows the background on "body" to be top/bottom 0
Set min-height on sidebar to avoid unstyled background
Set classes on the html element when the map is present
Updated selectors to set is-side-bar-active on html
Added note about changing the sidebar min-height
Merge pull request #94 from ox-it/new-spinner-css-fixes

New spinner & css fixes