Support >= and <= constraints in NetworkSimplex (#219, #234)

By default the same inequality constraints are supported as by
Circulation (the GEQ form), but the LEQ form can also be selected
using the problemType() function.

The documentation of the min. cost flow module is reworked and
extended with important notes and explanations about the different
variants of the problem and about the dual solution and optimality
conditions.

Support real types + numerical stability fix in NS (#254)

- Real types are supported by appropriate inicialization.
- A feature of the XTI spanning tree structure is removed to ensure
numerical stability (could cause problems using integer types).
The node potentials are updated always on the lower subtree,
in order to prevent overflow problems.
The former method isn't notably faster during to our tests.

Separate types for flow and cost values in NetworkSimplex (#234)

Support multiple run() calls in NetworkSimplex (#234)

Rework the interface of NetworkSimplex (#234)

The parameters of the problem can be set with separate functions
instead of different constructors.

Use XTI implementation instead of ATI in NetworkSimplex (#234)

XTI (eXtended Threaded Index) is an imporved version of the widely
known ATI (Augmented Threaded Index) method for storing and updating
the spanning tree structure in Network Simplex algorithms.

In the ATI data structure three indices are stored for each node:
predecessor, thread and depth. In the XTI data structure depth is
replaced by the number of successors and the last successor
(according to the thread index).

Internal restructuring and renamings in NetworkSimplex (#234)

Support min cost flow in dimacs-solver (#234)

Port NetworkSimplex from SVN -r3520 (#234)

Merge

Merge

Add more docs to LGF function interface (#109)

Fix in HaoOrlin (#264)

Improvements and fixes for the minimum cut algorithms (#264)

Merge

Rename max_matching.h to matching.h (#265)

Extend and modify the interface of matching algorithms (#265)

- Rename decomposition() to status() in MaxMatching.
- Add a new query function statusMap() to MaxMatching.
- Add a new query function matchingMap() to all the three classes.
- Rename matchingValue() to matchingWeight() in the weighted
matching classes.

Improvements for the Euler tools and the test file (#264)

Bug fix in the Euler iterators (#264)
Handle the case when the first node is isolated.

Imporvements for the matching algorithms (#264)

Merge

Merge

Rotate and enlarge some images (#262)

Add images + fixes in the doc of connectivity tools (#262)

Improve test files for some algorithms (#263)

Small doc improvements (#263)

Merge

Remove notes about reference maps as extra features (#190)

Exploit that the standard maps are reference maps (#190)

Standard graph maps are required to be reference maps (#190)

Various improvements and fixes (mainly in the doc) (#190)

Merge