Cleaning up work search code and centralizing in model.
Autocomplete gains a class method

Autocomplete gains a class method to remove any given string / values / prefixes from the results.

Using it to remove old records that have had the autocomplete relevant fields changed, in the sweeper.

Collections (name & title) and tags (name).
Changing some text to be a complete sentence.
Redirect to canonical versions of tags
Fixing issue 2911: subscriptions should be removed when their subscribables are. Added test.
Merge pull request #826 from brainwane/patch-1

Punctuation in work-search-date-help.html
Merge pull request #827 from brainwane/patch-3

Proofreading fixes in public/help
Merge pull request #828 from brainwane/patch-2

Punctuation in tag-search-results-help.html
Merge pull request #850 from CristinaRO/issue-2849-2893-autocomplete

Autocomplete gains a class method
Merge pull request #635 from sarken/issue_2821

Fix issue 2821 with hidden help for filters
Merge pull request #812 from anathomical/issue_2812

Issue 2812 fix.
Merge pull request #825 from sarken/issue_2675

Issues 2675 and 2830 adding bookmark blurb stats and collection info
Merge branch 'master' into issue_3190_elasticsearch

Conflicts:
	app/views/bookmarks/index.html.erb
Don't show private bookmarks on work/series pages
Posting a chapter expires tag pages

We'll vanquish you yet, Maurice!
Oops, must ensure there is a work and it's posted too
Merge pull request #842 from elzj/wordcount_spec

Moving word counter to its own class for test speed and great justice
Merge pull request #851 from elzj/issue_2911_deleted_subs

Fixing issue 2911: subscriptions to deleted objects
Removing any public-facing OpenID options
Outdated as they are, removing openid from unit tests