Fills in the ParameterFunction resource and updates CRD methods
Adds comments to all the fields in ParameterContext
Adds egg_uri field to parameter functions
Adds create_parameter to dataset management

In lieu of replacing the create_parameter_context, I opted to make one that caters to what we need.
In good practice we would refactor our usage to use this, but this is a patch-job to meet expectations.
Merge pull request #508 from ooici/preload-refactor

CIDEVSTC-49 - Refactors Parameter-based DM service methods to respect IonObjects