Allow users to select dataset collections in place of individual datasets for data tool parameters with multiple="true" enabled (if all elements of collection would be valid as input to this parameter).
Restrict collection reductions to flat collections. If a user wanted to reduce a nested collection they probably want to map of the subcollections reducing each and building a collection of the reductions. TODO: The sentence is probably unintelligiable, need to provide a concrete example.
A functional test demonstrating these reductions in included.