Quick and rough UI changes for source replies
Merge branch 'improve-source-lookup-page' of https://github.com/DonnchaC/securedrop into source-reply-ui

Conflicts:
	securedrop/source.py
Fix accidental breakage of select and selected actions on /col pages
Nit: return makes more sense than continue
Nit: unnecessary period
Nicer design for source reply area
Fix broken unit tests by removing unusued variable
Merge pull request #644 from freedomofpress/source-reply-ui

Source reply ui