Added missing functions in nodes-common.cc
Added missing functions in nodes-common.cc


Former-commit-id: 75f8cc32c6aa4310f0b8ac9470996364b386cf53
shuheik/dynet,xunzhang/dynet,shuheik/dynet,clab/cnn,xunzhang/dynet,xunzhang/dynet,clab/cnn,clab/dynet,clab/dynet,danielhers/dynet,chunyang-wen/dynet,shuheik/dynet,clab/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,chunyang-wen/dynet,chunyang-wen/dynet,clab/dynet,shuheik/dynet,chunyang-wen/dynet,danielhers/dynet,danielhers/dynet,danielhers/dynet,clab/cnn,shuheik/dynet,xunzhang/dynet,clab/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,danielhers/dynet