Tie validation into query construction

[jesserobertson]

Need to tie the validation into the query API

Problems:

• We want to hide the kludgy API that exists on the REST side (level1 etc) so will need to map these somehow - this will mean we need a list of valid keys for complex types
• How are we going to map valid values in complex types? at the moment we can tell where the problem is for arbitrary input but can't be pre-emptive about it.

Things to do:

• [ ] Split documentation up by query element ('reference', 'sample', etc)
• [ ] Add functionality to map unknown keys to a particular query element
• [ ] Tie in validation functionality