Added more checks in the bindings

bob/learn/em/MAP_gmm_trainer.cpp

bob/learn/em/ML_gmm_trainer.cpp

bob/learn/em/gmm_machine.cpp

bob/learn/em/gmm_stats.cpp

bob/learn/em/isv_base.cpp

bob/learn/em/isv_machine.cpp

bob/learn/em/isv_trainer.cpp

bob/learn/em/jfa_base.cpp

bob/learn/em/jfa_machine.cpp

bob/learn/em/jfa_trainer.cpp

bob/learn/em/kmeans_machine.cpp

bob/learn/em/kmeans_trainer.cpp