Add client API for Publication creation
Review follow up to Nico's review.

The arguments to createPublication() are now passed individually rather
than as a single object. The arguments have been restructured to be
avocet specific. As a result none of them are optional now. There are
still some auto-generated arguments which are required by Hilary for
now. This may change in the future at which point they can be removed.
PR Follow-up
Fix indentation in avocetheader.css
Turn the sign out link into a button
Merge branch 'master' of github.com:CUL-DigitalServices/avocet-ui into avocet/publications-client-api
HTML/CSS follow-up
Merge branch 'publications-client-api' of https://github.com/timdegroote/3akai-ux into publications-client-api
Follow up on client API
Merge origin/master and fix conflicts