some structured perceptron improvements / fixes
some structured perceptron improvements / fixes

amueller/pystruct,d-mittal/pystruct,wattlebird/pystruct,massmutual/pystruct,pystruct/pystruct,wattlebird/pystruct,massmutual/pystruct,pystruct/pystruct,amueller/pystruct,d-mittal/pystruct