This commit enables the workflow editor to deal with input collection data parameter types and inputs (easy) and much more complicatedly reason about mappings and reductions over inputs and collection inputs. Not sure I can really describe the new interface in a changeset - essentially it is more complicated to determine if a input can be connected to by an output - and that connection affects what are valid other inputs and what the outputs are.
Add abstraction into editor for use by galaxy.workflow.js to hide some editor details from workflow code and reduce duplication between add_node_for_tool and add_node_for_module.
John Chilton