Added hash and tree
Added hash and tree


Former-commit-id: 4f84c69f7f6fa37673d0c5f4e34343937823f54b
xunzhang/dynet,shuheik/dynet,chunyang-wen/dynet,xunzhang/dynet,chunyang-wen/dynet,danielhers/dynet,clab/cnn,clab/dynet,clab/cnn,clab/dynet,danielhers/dynet,danielhers/dynet,danielhers/dynet,xunzhang/dynet,shuheik/dynet,chunyang-wen/dynet,danielhers/dynet,xunzhang/dynet,danielhers/dynet,chunyang-wen/dynet,clab/dynet,clab/dynet,clab/cnn,clab/dynet,danielhers/dynet,shuheik/dynet,shuheik/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,clab/dynet,shuheik/dynet