Improved constructors for min cost flow classes
Removing the non-zero lower bounds is faster

Improve tree update procedure in NetworkSimplex
The new method updates a smaller subtree (fixing a bug) and shifting the
potentials with a costant value.

Backport doxygen options for version 1.5.7 from [9194a12c52e6]

Adapt the doc generation to the hg repo

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

Bug fix in min_cost_flow_test.cc

Doc improvements

Improve network simplex algorithm

- Remove "Limited Search" and "Combined" pivot rules.
- Add a new pivot rule "Altering Candidate List".
- Make the edge selection faster in every pivot rule.
- Set the default rule to "Block Search".
- Doc improvements.

The algorithm became about 15-35 percent faster on various input files.
"Block Search" pivot rule proved to be by far the fastest on all inputs.

G++-4.3 compatibility changes

Backport bug fix for Id handling from hg changeset [e67acd83a9ca]

Back port bug fix from hg changeset [0915721396dc]