Add soft min/max flow to LinkNode

[jetuk]

Feature request to add ability for a soft minimum and/or maximum node. This feature could be added to the basic node types: Input, Link and Output. When active it would create an additional internal node for the soft min and/or max.

[s-simoncelli]

I started to implement this for a Link node. Do we want the node to look like this internally?

Or is it simpler to just set one soft constraint and the user decides whether it is a min or max?

[jetuk]

I think the schematic is correct. I think you'll want it to only create the additional links if they are needed. It will probably be easier to keep them separated/dedicated for min and max for clarity and tracking (also if someone wants both?).

We'll need to ensure that the attributes correctly reflect these additional links.

[s-simoncelli]

Ok, my first implementation is in #213

[jetuk]

Completed in #213