Update ChangeLog.txt
Merge pull request #63 from opengm/master

update from opengm:master
update doxygen docu
Merge pull request #238 from joergkappes/master

 update doxygen docu
update doxygen
Merge pull request #239 from joergkappes/master

update doxygen
fix some warnings
Merge pull request #240 from joergkappes/master

fix some warnings
Merge pull request #3 from opengm/master

getting updates from master repo