Initial advanced search support and UI (#20)

Customizable search form using `q`, `author`, `name`, and `subject`
query parameters with custom autosuggest for each type (Lobid API).
Get facets from Lobid API, don't access ES index directly (#33)
Support faceted search over advanced search results (#20, #33)
Show filled advanced search form on top of results list (#20)
Don't apply owner filter on direct access to details view
Tweak advanced search controls and styles (#20)
Hide advanced search submit button, show after change (#20)
Tweak pagination and facets controls
Add intro text with description of different search options (#20)
Don't reuse input field value when adding a search criterion (#20)
Fix typos in intro text
Improve UI for adding and removing advanced search criteria (#20)
Set z-index CSS property to make sure autosuggest is always on top
Merge pull request #50 from hbz/issue-20-advanced

Advanced search support and UI