Support tolerance technique for BellmanFord (#51)

A new operation traits class BellmanFordToleranceOperationTraits
is introduced, which uses the tolerance technique in its less()
function. This class can be used with the SetOperationTraits
named template parameter.

Merge #332

ArgParser can throw exception instead of exit(1) (#332)

Better return type for cycleLength() functions (#179)
in the min mean cycle algorithms.

The original Value type is used instead of the LargeValue type,
which is introduced for internal computations.

Merge #340

New heuristics for MCF algorithms (#340)
and some implementation improvements.

- A useful heuristic is added to NetworkSimplex to make the
initial pivots faster.
- A powerful global update heuristic is added to CostScaling
and the implementation is reworked with various improvements.
- Better relabeling in CostScaling to improve numerical stability
and make the code faster.
- A small improvement is made in CapacityScaling for better
delta computation.
- Add notes to the classes about the usage of vector<char> instead
of vector<bool> for efficiency reasons.

Merge bugfix #336

Fix the date field comment of graphToEps() output (#336)

Modify the header of scripts/bib2dox.py (#184)

Merge

Fix LpBase::addRow(Constr) (#334)

Merge bugfix #337

Use void* like LPX object (#337)

Merge

Handle graph changes in the MCF algorithms (#327)

The reset() functions are renamed to resetParams() and the new reset()
functions handle the graph chnages, as well.

Merge

Doc improvements for planarity related tools (#62)

Port planar image from SVN -r3524 (#62)

Merge

Add doc for the traits class parameters (#315)

Add more information on Makefile variables (#316)

Add a warning about huge capacities in Preflow (#319)

Merge #180 and a bugfix in #51

Small bug fixes (#180)

Rename a private type in MCF classes (#180)

The new MCF algorithms define a private map type VectorMap,
which could be misleading, since there is an other VectorMap
defined in lemon/bits/vector_map.h. Thus the new type is
is renamed to StaticVectorMap.

Adds tests for the new MCF algorithms (#180)

Rework the MCF test file to help extending it (#180)

Fixes in the heap concept to avoid warnings (#180)

Add citations to CycleCanceling (#180, #184)

Entirely rework cycle canceling algorithms (#180)

- Move the cycle canceling algorithms (CycleCanceling, CancelAndTighten)
into one class (CycleCanceling).
- Add a Method parameter to the run() function to be able to select
the used cycle canceling method.
- Use the new interface similarly to NetworkSimplex.
- Rework the implementations using an efficient internal structure
for handling the residual network.
This improvement made the codes much faster.
- Handle GEQ supply type (LEQ is not supported).
- Handle infinite upper bounds.
- Handle negative costs (for arcs of finite upper bound).
- Extend the documentation.