Merge pull request #37 from DerThorsten/RC2.1

Rc2.1
bugfix ibfs maxflow
Merge pull request #38 from joergkappes/RC2.1

bugfix ibfs maxflow
update FindCPLEX
Merge pull request #39 from joergkappes/RC2.1

update FindCPLEX
buxfix dualdecomposition with float and unittest with float
Merge pull request #40 from joergkappes/RC2.1

buxfix dualdecomposition with float and unittest with float
Merge remote-tracking branch 'upstream/RC2.1' into RC2.1
fixed compile bugs which where detected by clang++ but not gcc