Add Search Studies object

This object has natural language parsing for searches and returns a dictionary of {study_id: [samp1, samp2, ...]} of samples and studies matching the search query. An example query is also in the documentation, showing you can get pretty complex with them.
That's really cool, thanks. I've tweaked the current LIKE statement, and will look into the security for adding a "similar" search code for regex in the future. That shouldn't be blocking, so I'll make an issue.