Added datastore query constants
CIDEVSTC-306: Enhancements to resource and association queries
CIDEVSTC-306: Enhance event queries
CIDEVSTC-306: Provide recursive resource and association queries
CIDEVSTC-306: Provide parameterized datastore queries
Added datastore query to pyon.public
Merge pull request #509 from mmeisinger/add306_disc

CIDEVSTC-306: Enhancements to resource and event queries