Update collections index to match front page table, and add tags column.

refs #1511
Add AJAX tag search box to collections.index page.

refs #1499
Fix crash if no search parameter given.

refs #1499
Update query in browser location bar when showing search results.

refs #1499
Unescape filenames from manifests. refs #1849
Add collection search box on home page.

refs #1499
Merge branch '1499-workbench-tags'

closes #1499