Add simple renaming of fields in search box; speed up JS processing while typing in search box.

- Sometimes you don't want users to have to type blah.name.raw into the search box to search a field. Can now remap user field names.
eg:
searchQuery.fieldNameMap = [
  { "user_field": "author:", "index_field": "author_login:" },
  { "user_field": "tag:", "index_field": "tag.name:" }
];

- Typing in the search box was getting way to slow with some of the newer features