Consider incorporating pouchdb-find selectors

[brettz9]

These look like they could come in handy: https://github.com/nolanlawson/pouchdb-find

[aaronpowell]

isn't that what PR #152 is about?

[brettz9]

That PR is increasing the situations (i.e., to Server.count and Server.get) where our existing range selectors can be used, but the pouchdb-find has additional selectors so just making a feature request for considering those selectors.