cleaned up CSS comments
temporarily removed masthead and banners; added crossgrid classes to CSS
hard-wrapped html files in /core/doc/ TODO: all other files
updated and hard-wrapped TODO lists
updated TODO
Merge branch 'masthead' into hotfix

Conflicts:
	core/styles/all.css
	core/styles/typo/_body.less
added durations to resume

TODO: hard-wrap resume source
hard-wrapped resume source
removed Liquid from HTML source
updated TODO
reformatted some documentation
hard-wrapped home pages
conform math7 index and pacing guide to site-wide styles

TODO:
- math7 main pages (syllabus, standards)
- math7 sub pages (unit overviews)
- (optional) math7 lessons
updated unit 6, index, and todo
abstracted caption borders
abstracted quasi-paragraph borders
Merge branch 'hotfix' into typo
conform unit overviews to site-wide styles
styled syllabus
styled top-level pages TODO: individual lesson pages