test ApplicationHelper#tag_links_for
test ApplicationHelper#datestamp.
test and refactor EventsHelper#tweet_text.
test EventsHelper#today_tomorrow_or_weekday.
refactor MappingHelper.
remove untested and unused relative option in TimeRange.
test SourcesHelper.
the id is germane to the test.
force deterministic tag ordering.
test SiteController.
minor refactor.
test VersionsController.
Merge pull request #178 from botandrose/coverage

Increase test coverage