Web study search interface - NEED FEEDBACK

This pull request is rather large, so sorry about that. It adds a ton of functionality to the study selection page, including the ability to search and select samples by metadata, select multiple data-types per study and multiple processed data files per data-type, and database updates for selection/deselection as well as the ability to continue selecting samples after leaving and then returning to the analysis pipeline. 

Currently I need people to play around with the page functionality and give input on what is broken/wonky, what needs to be changed interface-wise, and what needs to be added. 

Known issues:
 - Use [chosen](http://harvesthq.github.io/chosen/) for the multi-select boxes for each data-type
 - Have some tooltip or other way of seeing the pertinent values for processed data
 - Have some way of knowing what metadata categories are available to search over