First draft of a filter node factory - not working yet

I've updated the nuget packages to the latest development versions, which will have the Copy Local flag set to false.
That way no vvvv dependencies (including SlimDX and MEF) should end up in the output folder - only dependencies from the image pack itself.
Split up project files into core and nodes.

Node factory gets loaded correctly now.
Set Copy Local flag to false on various dependencies which are already in core.
Node factory working - see gaussian blur.
merged elias factory changes
started editing help patches
started editing nodes to factory format, rename ImageLoad to FileImage
support more attributes for Instances
rename ImageLoad to FileImage