Allows M/R jobs in popHealth to use prefiltering

This pull request allows popHealth to take advantage of the prefiltering support
that has been built into QME and HDS. It is configurable, and on by default, in
config/popHealth.yml.

When prefiltering is enabled, a query is created based on the CQM logic. This
query will be passed to MongoDB as filter for documents to run through the Map
Reduce job. Depending on the measure, this can have a big performance
improvement on measure calculation times.

This commit switches the pointers to HDS and QME in the Gemfile from fixed
versions to their git repos. These should be changed when the gems with the new
functionality are released.
search by category or measure titles #8
clear float left after the search input box
fsearch is now .form-control, on its own line, with placeholder. added clear search button. search is now case insensitive. search is triggered by keyup
convert span to button
Merge branch 'yoon_measure_search'; fixes #131
Merge pull request #160 from pophealth/enable_mr_prefiltering

Allows M/R jobs in popHealth to use prefiltering
Added code to support orphan provider at the top level to ensure proper result display. 

Also added config option to populate the root and extension of this provider.