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.

 #!/bin/bash

 echo '#include<'$1'>' >seedeps_tmp.cc

 gcc -MM -I. -I.. -I../.. $2 seedeps_tmp.cc|tr ':' ' '|tr '\' ' '|tr ' ' '\n'|

 egrep -v '^$'|egrep -v '.o$'|egrep -v '.cc$'|grep -v '^'$1'$'|sort

 rm seedeps_tmp.cc