First implementation of revised menu

Uses CSS transforms for much faster transitions. No longer causes text to reflow.
Fixed extra whitespace that appeared above header
Changed menu animation to exponential out
Aligned site's title and hamburger button on mobile

This uses CSS transforms so it's incompatible with IE < 8. That's probably not a problem though since this is for mobile devices.
Increased tap target size of hamburger button
Added a subtle drop shadow to the hamburger menu
Made menu instructions visible on mobile devices
Fixed white space around hamburger
Merge branch 'faster-menu'