Freetext and'd search (updated)

--fixed bugs mentioned by @DavidEBest and removed ui.json file.
Old notes:
Added free text search
-- searches descriptions and titles of projects and tasks, all terms are and'd in this search
-- also free text searches tag names, all terms are or'd in this search
-- still uses the select2 autocomplete which shows tags as you type, but the tag icon is removed if an existing tag is selected and it is effectively treated like a free text search

Replaces #426 

Addresses #341 .