Improve search, results and filtering by adding taxon and clique identifier count information

[gaurav]

This PR combines several improvements to search, results and filtering:

• It updates the search query to no longer duplicate the search query when doing an autocomplete query (see "Bone" works well when autocomplete=true but breaks when autocomplete=false #142).
  • This breaks hyphenated search terms in the autocomplete query, and I can't figure out why. For now, I've set it up so that we replace special characters with spaces in the autocomplete query (i.e. beta-secretase becomes (beta secretase*)) but we escape special characters in the non-autocomplete query (i.e. beta-secretase becomes (beta\-secretase*) since that still appears to work. I'll dig into this more deeply in Hyphen processing still a bit dodgy, possibly because of our choice of tokenizer #146.
• It adds taxon and clique identifier count to values indexed during data loading.
• It incorporates clique identifier count into both the returned results as well as the boosting and sorting of the returned results. It also tweaks the boosting values used in query fields and phrase fields.
• It adds an only_taxa input field that allows filtering results to a list of NCBITaxon taxon identifiers (note that this will only work for terms that have taxon information, which at the moment is only cliques containing NCBIGene identifiers).