Merge pull request #44 from joergkappes/RC2.1

Rc2.1
factorMarginal and marginal used FactorType but must use IndependentFactorType, or virtual inference interface will be overwritten
Merge pull request #46 from DerThorsten/RC2.1

ASTAR factorMarginal and marginal used FactorType but must use IndependentFactorType
added a pretty table printer for factors and functions using prettytable
moved python shape walker to a single file
started to export inference with Integrator as accumulator
Merge pull request #47 from joergkappes/RC2.1

Rc2.1
Merge pull request #48 from joergkappes/RC2.1

add alpha-expansion-fusion and orderreduction code by Alexander Fix
Merge branch 'RC2.1' of git://github.com/opengm/opengm into RC2.1
replaced deprecated PyArray_FromDims with PyArray_SimpleNew
fixed bug in numpy array allocator, a delete[] was missing
added constructor with default paramter, and used visitors in the way it should be
made docu up to date
made from python converter better
- exported mqpbo to python
- added "integrator" as accumulator for inference
- added marginal and factorMarginals members to Bp and Trwbp
- added integrator for adder and mupltiplier for bp and trwbp
- added partial optimality for qpbo-external and mqpbo
fixed minor bug in python doc
fixed minor bug in python doc
added missing visitor.end()
added missing visitor.begin and visitor.end , even if there is nothing to visit
added missing LabelVector