expanding descriptor documentation
implementing query method, and mode query method descriptor
moving column query expression evaluator out of column descriptor
adding test around query expressions
adding query method argument validation and supporting tests
adding more tests around query method behavior
adding additional tests around query method
rolling all query types into the filter method and removing the query method
updating the get methods to work with query expressions
adding additional tests around the query expression queries
changed __contains__ to in_()
Merge branch 'master' into query-builder
Merge pull request #68 from bdeggleston/query-builder

Adding support for query expressions