pipe and belt autoconnect

[goertzenator]

Someone in the general section was just complaining about not being able to run parallel pipes and it got me thinking about a solution:

1. Shift-Right-click on an existing pipe you want to connect to. This selects the pipe as the "context pipe."
2. Place a new pipe beside the context pipe. The new pipe only connects to the context pipe and to any machines, never to any other adjacent pipes.
3. The newly placed pipe becomes the new context pipe.

This way you can snake new pipelines through heavily congested areas and you won't connect to other pipes.

And this can also be applied to belts so you can quickly lay down a belt path without constantly hitting R.