Added getter/setter utils.js methods for local storage

This is primarily proactive; there are only a couple of places in the code
that use local storage, but I wanted to nip it in the bud now and use
helpers instead.

Closes COUCHDB-2432
Moved Add Section button on Config page to header.

Closes COUCHDB-2421
Fixes back button from edit document

Closes COUCHDB-2427
Fix for page body widths being incorrect on Stats #2

This is the second version of this ticket that doesn't contain
whitespace fixes.

As noted in the ticket, the widths of the main body of the Stats
and Accounts page were incorrect. On the stats page, the rightmost
column was offscreen; on the Accounts page the text gets cut off.

This ticket fixes the stats page. The Create Admins page still
has the text get cut off. This is unrelated to this issue - I'll
fix that in a separate ticket (COUCHDB-2417).

Closes COUCHDB-2428
Account page style and usability fixes

This ticket is a general style clean-up of the Accounts page. Namely:

- general CSS style fixes
- sidebar styles now consistent with other pages in app
- focus is placed on first text box on page when page load (N.B.
autofocus wouldn’t work consistently, hence the JS)
- "Databases" left nav item no longer selected

*** Please note: the Create Admins page is still having it's text cut
off. This will be fixed once PR #123 has been merged. ***

Closes COUCHDB-2417
Fix for API Urls on Stats, Config and Replication pages

Closes COUCHDB-2439
Whitespace and style fixes

Updated styles for the Active Tasks add-on.
- ‘ not “
- underscore comments
- whitespace fixes
- removed a couple of unused vars
Remove API Url link from header on Access Denied page

Closes COUCHDB-2436
Unify one_pane and one_pane_db again

We recently introduced a new template `one_pane_db` which had
the rightHeader for the list of DBs. In retrospective it turns
out that also other views need the rightHeader markup to
populate it with elements.

Views that don't need the rightHeader element should not get
influenced so this removes some complexity and avoids that the
templates diverge more in the future.
Replicate icon on Databases page now redirects properly

Closes COUCHDB-2437
Fix path for ZeroClipboard

If deployed as an CouchApp, the path for ZeroClipboard did not
match

Steps to reproduce:
 - run `grunt couchapp_deploy` with a Couch in Admin-Party
 - open http://localhost:5984/fauxton/_design/fauxton/index.html

Closes COUCHDB-2323
Whitespace & style fixes
Fix back-button after you saved a new document

When you were creating a new document and then clicking save
the back button would bring you to the editor for new documents.
To get back to the Documentslist you were coming from, you had
to hit the "back"-button twice.

Additionally renamed lastPage to lastPages as it contains
multiple pages.
Write up expectations we have for contributions

 - mention styleguide
 - mention commit message format
 - small bugfixes do not need a Jira ticket
Replaced couple of hardcoded vars with constants
Moved Add Config Option modal to tray

This also fixes a few things.
- validation is cleaned up a bit
- the typeahead option now properly works again for sections.

Closes COUCHDB-2443
New lookahead-tray component

You can see the component by going to a database, then clicking on
the database name. That will open up a tray where you can type to
get a list of other matching databases. Clicking <enter> or
selecting the item from the list will take you to that particular
DB page.

Closes COUCHDB-2420
Create generic Tray component

This moves a lot of the logic from the individual trays (Add Database,
Query Options, API Url) and into a generic Tray component.

Closes COUCHDB-2401
Fix for Query Options search

Closes COUCHDB-2451
Add Option tray now uses generic component

To test this, just click on the Add Option header link on the
Config page.

Closes COUCHDB-2453