Updated left nav highlighting

Only the top-most active item should be highlighted now. Still need to
do some work to fix some minor bugs due to floated items causing
incorrect sections to highlight.
Fixed Left Nav and Center Director Styles

Finished cleaning up the left nav highlighting, and cleaned up the
styling for Center Directors on Meet the Team pages.
Merge branch 'find-a-doctor'
Merge branch 'master' into mobile-retrofit