Fix of concatenate when only some of the inputs are batched
Fix of concatenate when only some of the inputs are batched


Former-commit-id: 93eaab3e08ab7d938857446e7c5bfa7507737308
chunyang-wen/dynet,clab/dynet,danielhers/dynet,clab/dynet,clab/cnn,xunzhang/dynet,shuheik/dynet,clab/dynet,xunzhang/dynet,clab/dynet,xunzhang/dynet,danielhers/dynet,xunzhang/dynet,shuheik/dynet,clab/dynet,chunyang-wen/dynet,clab/dynet,shuheik/dynet,chunyang-wen/dynet,danielhers/dynet,clab/cnn,danielhers/dynet,danielhers/dynet,danielhers/dynet,danielhers/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,clab/cnn,chunyang-wen/dynet,shuheik/dynet,shuheik/dynet