big refactor part 1

common base class for DSFunction and DSVarArgFunction
fixed some broken unit tests
big refactor part 2

custom nodes now share same base class as DSFunction and
DSVarArgFunction
force resharper nunit runner to use x64 bit

fixes protogeometry test failures
big refactor part 3

everything is working again
unit test fixing
small bug-fix
make sure we check Definition not Controller
another case of Controller vs Definition
Revert "Revert "Partial Application for Multi-Output nodes""

This reverts commit 7c105fc8b15602bedeb7664fdbe0be6e51696a2d.
Merge remote-tracking branch 'origin/partial-multiouts' into functioncall-refactor

Conflicts:
	src/DynamoCore/ViewModels/WorkspaceViewModel.cs
fixing some merge wonkiness
fixed proxy custom node null ref
fixed broken preview for some single-output nodes
fixed broken watch output
fixed broken unit test for exec interval
fixed a ton of unit tests
added "csv" to abbreviations list
build fix
more unit tests