Merge pull request #211 from joergkappes/RC-2.3

Rc 2.3
Merge pull request #213 from joergkappes/RC-2.3

Bugfixes External Libs
Merge pull request #22 from opengm/RC-2.3

from RC-2.3 to my master
changed visitos to new interface (not yet all)
changed visitos to new interface (not yet all)
changed visitos to new interface (not yet all)
added missing file
implemented mqpbo with new visitor
changed gibs with hotfix to new visitor interface
renamed visitor to visitors in gibbs
Merge branch 'master' of github.com:DerThorsten/opengm
removed example gibbs
removed example gibbs
removed sw and gibbs from cmd min sum
removed sw and gibbs from cmd min sum
maybe fixed trws
maybe fixed trws
maybe fixed trws
removed sw from visitors
Merge pull request #214 from DerThorsten/master

changed visitors to new