Update view api

Updates based on comments in https://github.com/kite-sdk/kite-docs/pull/63 .
I think calling something out as "user-friendly" is like saying it's "easy". It's all relative. Kite lets you express expectations (or predicates, or constraints) with a *readable* API, and will correctly load records for you.

The part about partitions you specify isn't quite correct. Kite automatically determines the partitions to use based on the constraints for a view. The benefit is that the user doesn't have to specify them. For example, if you're searching for events based on time and you've partitioned by time, Kite automatically knows how to filter out partitions that can't match.