Major improvement in the cost scaling algorithm

- Add a new variant that use the partial augment-relabel method.
- Use this method instead of push-relabel by default.
- Use the "Early Termination" heuristic instead of "Price Refinement".

Using the new method and heuristic the algorithm proved to be
2-2.5 times faster on all input files.

Bug fixes is HaoOrlin and MinCostArborescence

MinCostArborescence
- proper deallocation
HaoOrlin
- the target needn't to be the last in its bucket
- proper size of container (if each node starts in different buckets initially)

Add missing pointer initializing in min cost flow classes

Fix _setCoeff