Adding roots.io base wordpress theme

See http://roots.io/
Initial customizations of roots theme
Updated css transitions for search input
Updating CSS and base data for search input marquee
Reworking the header to match mockup
Theme logic for placement and style of search box
Merge branch 'phil-roots' into staging
Header css/layout updates
refining header nav css/layout
Restructuring header for new layout
More layout updates
Merge branch 'phil-roots' of https://github.com/GSA/data.gov into design-vz