Add decomposable aggregate syntax to myrial
Use a named tuple for decomposable udas
Add some sanity checking of argument lists
Check arity of remote aggregate emit list
Check for duplciate decomposable aggregates
Move stateful function resolution to a helper function
Rename field in aggregate state struct
Add an index to LocalAggregateOutput
Remove the SingletonEmitArg class
Use an ordered dict for statemod references
Merge branch 'whitaker_uda_combiner' of github.com:uwescience/raco into whitaker_uda_combiner