Fix sidebar design
Fix sidebar design

- Make height of red & grey items in sidebar equal
- Allow scrolling down to the bottom of the list when window height is small
- Better vertically aligned icons
- Also show brown padding between burger and list when scrolled down

Closes COUCHDB-2402

benkeen/couchdb-fauxton,michellephung/couchdb-fauxton,cloudant/couchdb-fauxton,michellephung/couchdb-fauxton,benkeen/couchdb-fauxton,robertkowalski/couchdb-fauxton,popojargo/couchdb-fauxton,cloudant/couchdb-fauxton,garrensmith/couchdb-fauxton,robertkowalski/couchdb-fauxton,popojargo/couchdb-fauxton,cloudant/couchdb-fauxton,popojargo/couchdb-fauxton,michellephung/couchdb-fauxton,robertkowalski/couchdb-fauxton,garrensmith/couchdb-fauxton,cloudant/couchdb-fauxton,apache/couchdb-fauxton,popojargo/couchdb-fauxton,garrensmith/couchdb-fauxton,garrensmith/couchdb-fauxton,apache/couchdb-fauxton,apache/couchdb-fauxton,apache/couchdb-fauxton,robertkowalski/couchdb-fauxton,benkeen/couchdb-fauxton,michellephung/couchdb-fauxton,michellephung/couchdb-fauxton