Styleguide update

Now mentions to always use this.$("...") within Backbone Views.
Refactor Nightwatch

This ticket makes a few changes to the way Nightwatch is set up:
1. the main Nightwatch settings (username, password, login URL, key
nightwatch setup file locations) are moved to the settings.json
file to allow them to be defined a single global place and overridden
if need be.
2. it now dynamically determines the list of tests to run based on
content of settings.json.
3. hardcoded username, password & URL moved from helpers.js and
loginToGUI.js and now loaded from settings.json file

Closes COUCHDB-2481
remove nightwatch.json

it keeps beeing changed
Componentize footer

Take the elements that were all baked into all-docs-list
and inject them into the all-docs-list. This enables us to have
a separate footer component in the layout which can be initialized
without the all-docs-list viewobject.

This enables us to remove the `position: fixed` from the footer
and use `position: absolute`. Without having the element
`position: fixed;` we do not need to calculate it's width via JS
and can apply a css based pane layout.

Part of: COUCHDB-2471
fix scroll issues
changes from review
whitespace fix