yet another round of fixes for signed-unsigned comparisons
yet another round of fixes for signed-unsigned comparisons

agra-uni-bremen/metaSMT,hoangmle/metaSMT,agra-uni-bremen/metaSMT,finnhaedicke/metaSMT,nbruns1/metaSMT,finnhaedicke/metaSMT,hoangmle/metaSMT,hoangmle/metaSMT,nbruns1/metaSMT,finnhaedicke/metaSMT,nbruns1/metaSMT,agra-uni-bremen/metaSMT