updated schedule language, included NRPA as advisor
removed option to express interest in the Request for Comment period
added NRPA logo
updated nrpa logo
added strikethrough style to now-past closing date
updated all references to PLATS and Public Land and Trail Spec to OpenTrails and Open Trail System Specification, respectively:
updating spec.html to reflect the latest version of OpenTrails
updated file names on spec page
testing addition of subheader indicating required files
added discussion group link to spec home page
added indication as to whether each file is required to spec.html
updated title of introductory post
added short name to headline announcing name of spec
Merge branch 'trail-spec-page' of https://github.com/alanjosephwilliams/codeforamerica.org

Conflicts:
	specifications/trails/spec.html