Changes

Attempt to prevent pipes from tossing excess

This NEEDS extensive testing. I only have a vague idea how this code
works.

The original code was just tossing any power beyond what it could
handle, with no throttle on how much it was requesting from its
neighbors.

I think its working, more or less, but you'd probably have to hook it to
some TE Cells or something to know for sure.
 (commit: 7336dfd)