Change "conditional adapter" to use mongodb-query-like adapter

[sendyhalim]

It's cool that we can define conditional validation rules, unfortunately it uses some kind of odd and bizarre conventions (hint: I'm looking at you https://github.com/sendyhalim/noes#nested-example). I personally think mongo-db-like query logic has one of the best and most understandable logical format.

https://github.com/protobi/query#basic-usage would be a better fit

Note that this would be a breaking changes. Another approach would be to provide a public API to set custom "conditional adapter".