Mapr config not hardcoded

This removes the hard-coded temp mapr config and instead loads it via JSON using https://github.com/ome/omero-mapr/pull/46

Full testing of gallery:

/gallery/ home page loads various "categories" of studies. Thumbnails load OK. Top links to cell / tissue and big "image" links to cell and tissue.
Click on Cell-IDR / Tissue/IDR -> goes to similar looking page, apart from big "image" links are not show. Title should say what page you're on. Categories are the same but only show cell/tissue subset of studies. If category is empty it's not shown. Top-left link goes back to homepage.
Search (from home page): try with "Study Attribute". When attribute is chosen from list, auto-complete should show list of options immediately. Then filter these when you type. If you hit Enter or pick an option from the auto-complete list, go to /search/ page with the query in URL. Should show search results.
Search again (e.g. pick a different Attribute or type in different value). Filtering happens "on the fly" for Study attributes. Hitting enter or picking one will update the URL. Can use browser back/forward buttons to see previous searches. Page should update accordingly each time.
Search with "Image Attirubute (via MAPR) from the home page / cell / tissue. Searching from /cell or /tissue pages will go to cell/search/ or tissue/search and filter on the subset of studies.
MAPR auto-complete should lookup matching terms. Picking one will filter studies.
If all studies are filtered out on /cell or /tissue page, a link should take you to the other page with the same query.

ome / omero-gallery