Add inputs and outputs to the graph

[trams]

This is an attempt to show inputs and outputs in the flow diagram.

It is not very pretty. For one I didn't add any pictures for sources and sinks.
Also it contains a hack to filter __pipeX__pipeY outputs which may not work on your cluster

Apart from this it works perfectly and makes the diagram much more useful, especially for one step jobs.

[dossett]

@trams Thank you for your many recent PRs! I merged a couple of them already, and will come back to the others after we get 1.1 released.

[trams]

@dossett thanks! I'll wait for 1.1 and then try to rebase

[nixsticks]

Hey @trams, thank you for all the contributions you've made! This is a great idea but I'm hesitant because it makes graphs of moderate or larger size look quite unwieldy. If you have thoughts on how to improve the UX on that, we'd love to hear them.

[trams]

Just out of curiosity what is the size of moderate graph? Most of our jobs contain around 3-5 steps and it look okayish (I didn't look for a proper picture for input|output)

[nixsticks]

@trams Many of our jobs are much larger than yours it sounds like -- a moderately-sized one would be around 10-15 steps for us(!)