Update map control positioning.
wip
Anchor SVG to bottom left
Change header BG color to pure white.
WIP: Intro screen show/hide w/out animation.
Consolidate nav into scrolling coordinator.
- fixes bug where you would be brought back to 
about page after clicking a different nav link from
the splash screen
Anchor logo from bottom.
Fix Transitions in Safari.
- header height can not be transition, use min-height instead.
- had to make st-width static position to stretch to full height.
- add -moz and -webkit prefixes to transitions