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
Fix lookaheadTray

It wasn't showing up on click
Remove checkboxes from viewlist

The viewlist has no bulkdelete. If we want to add it as feature a
good point might be with the new header-controls.
Revert "Fix the flash on doc page route changes"

This reverts commit 84e6d87b2de671fff1ddeaffb02003ef2ffd0b09.
wip
with-tabs-sidebar