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.

 Document: lemon-refman

 Title: LEMON Reference Manual

 Author: LEMON Development Team

 Abstract: Documentation of LEMON.

 Section: unknown

 Format: HTML

 Index: /usr/share/doc/lemon/html/index.html

 Files: /usr/share/doc/lemon/html/*.html