Support multiple values per key+solution

We've outlined our current solutions here:

The most important ones now are the rest of the simple property/operator syntax and the plus cards.

Some of that might not make a ton of sense if you haven't gotten your head around CQL Syntax.

We'll be implementing this over more than one release. For Wagn 0.13, we implemented Support multiple values per property, e.g.:

{"type": ["in", "User", "Company"] }