Squeeze left-hand column to 220px

This necessitated making the title of one of the Tizen IVI
tutorial pages shorter.
Basic resizing + left menu hiding
Get menu collapse working when screen <= 600px
Don't show menu collapse button on home page
Add drop shadow around menu when page is narrow
Add graphic for collapsed menu button
Fix some CSS which broke during merge
Layout tweaks for Firefox

Firefox seems to need elt.style.paddingTop instead of
elt.style['padding-top'].
Close submenu in response to clicks off the submenu
Merge pull request #89 from townxelliot/responsive-871

Make design responsive
Split Windows and Linux instructions apart