Global notifications now full width

This makes a small change to the global notifications so that it goes
full page width. This was done partly to solve the missing close "x"
that was getting put off screen, but also because it just looks better
this way.

Closes COUCHDB-2473
Cleanup: remove unused index.html

I first noticed an unused footer element, but it turned out that
the whole `index.html` file was unused (it is now generated by
`index.underscore`)
Replace .execute() for .click() behavior in Nightwatch tests
Cleanup: Remove unused nv.d3

stats are removed now and we don't use it any more

Closes COUCHDB-2355
New design for docs

Port from #33:

Based on the work of Jenn Schiffer <jenn@pancaketheorem.com>
(@jennschiffer), Sue Lockwood <deathbear@apache.org>
(@deathbearbrown) and Sean Barclay (@seanbarclay)
Fix the flash on doc page route changes

This is subtle and only occurs on Chrome. To reproduce:
1. Go to the Database -> All Docs page for a database.
2. Click from the All Documents page to All Design Docs.

Click back and forth a few times. Notice that sometimes there's a
sort of quick flash that appears over the breadcrumbs section making
it look a little like the breadcrumbs are being re-rendered.

Closes COUCHDB-2467
Nightwatch test to test lookahead component
Remove duplicated notifications

The ones that are used are in index.underscore

COUCHDB-2471
Fix URL paths for Views to be _view not _views

This changes the URL paths for Views within Fauxton for compatibility
with the API URLs.To test, just create/edit a View and confirm the URL
ends with /_view/theViewName not _views/theViewName

Closes COUCHDB-2415
Move Helpers.docs into constants.js

This is a house cleaning ticket. It does a couple of things:
1. Moves the list of URLs stored in Helpers.docs into constants.js
2. Refactors constants to group the (now growing) list into appropriate
groups.

Now there are a lot less hardcoded "magic" strings throughout our
code, yay!

Closes COUCHDB-2474