Adds pipe manifolds. The first few pipe sections on either side of a pump greatly restrict the total available flow rate, making high flow networks problematic to construct. Manifolds allow additional connection points at pump suctions and discharges, enabling efficient long distance parallel flow networks.

Some notes for more effective use:
- The flow of a single long-range pipe run rapidly tapers off to 1000 units/sec at 200 tiles. This can be 200 standard pipes, 100 underground pipe sections (max distance 1000 map tiles), or any combination thereof.
- Never exceed 200 pipe tiles on any single pipe run. Flow falls off sharply after the 200th tile. Manifolds themselves count as a 'tile' for the purposes of this calculation.
- When connected via a manifold, a set of 5 offshore pumps can see maximum flow (6000 units/sec) through 6 parallel underground pipe sections across 1000 map tiles (31.25 chunks).
- Need longer distances? Simply make a pumping substation by ending the parallel sections into a manifold, then a pump, then another manifold, then resume your parallel section for another 1000 map tiles.
- Avoid connecting manifolds to other manifolds unless there is a decent overlap (>1 connection). Flow behavior is similar to that of connected tanks. Best performance is seen with pumps assisting with flow (but far less are needed than would be without this mod).

Thanks go out to:
- kovarex, for patching a bug that made it possible to implement this mod.
(https://forums.factorio.com/viewtopic.php?f=11&t=48315)
- posila, for working on another issue related to future expansion of this mod.
(https://forums.factorio.com/viewtopic.php?f=182&t=52211&p=305142)

Please provide feedback/bugs/etc. in the discussion section for this mod.