Let winches work once the unexpected child part is decoupled.

Previously placing a non-port part below the winch in the stack
permanently broke it. Now it should be possible to use a decoupler
to continue the stack.
Allow using KAS pipes as field substitutes for fuel lines.

When linked, either end of the pipe now has a context menu option
that allows enabling or disabling fuel flow in that direction.

Pipe ends attached from EVA in previous versions have to be grabbed
and reattached to use this feature, or the button will complain about
dangling ends.