Sidebar improvements

Some UX improvements to the sidebar in a database view
Implement a filter for databases

Uses a new model to manage the state of the different search
filters to filter the view.

Nice feature: the filter for the database (upper input) and
the filters for the type (buttons) work nicely together,
so you can filter out all replications for that
database (let's name it registry)  without the compaction,
if you choose replication as type and enter "registry" in the
top input.

Closes COUCHDB-2125
Provides grouping and better formatting for design doc metadata

Fixes COUCHDB-2174.
couchapp@0.11.x

removes the horn on push which breaks on linux
Disable async rendering to fix race conditions
Fix navbar icons padding
Fix align for active tasks progress bar and button
Fix double render when a new template is rendered

This fixes the double render issue we are getting. This is very
noticeable on a first render. The fix is to wait for the layout to
rendered and then only render the views.
Fix failing tests
Api bar improvements

If the api bar is visible and a user clicks elsewhere it closes.
Also use correct icons
API URL style updates, added Velocity.js (http://julian.com/research/velocity/) for use on animated transitions
Code improvements from PR
Fix API bar buttons color
Hide api bar correctly when api-url-btn clicked
Implement new database view

New database view. This is based off of the work from deathbearbrown
<deathbearbrown@gmail.com> and Jenn Schiffer <jenn@pancaketheorem.com>.
Make velocity dependancy of velocity.ui
Improve velocity dependancy managements
embed velocity.ui into jquery.velocity.js
remove console.log
Devserver: do not throw on cancelled request

Catch error on a destroyed socket write, this happens for example
if you type in too fast on a typeahead-element which is asking
every time for a list of databases