Rebalance Buffer Lanes

Rebalance buffer lanes are similar to normal buffer lanes but are only used when moving supply from areas with excess to areas with a shortage; they are defined as a reasonable set of from/to pairs, limiting the engine to only moves the user approves. For example, if inventory is normally transferred from a warehouse to stores, a buffer lane is defined as the connection between the warehouse and the stores. But when a store with excess inventory transfers some quantity to a store with a shortage, that is a rebalanced buffer lane.