model.cc now allocates parameters in a memory pool
model.cc now allocates parameters in a memory pool


Former-commit-id: 79a6c620102fb2fa50ae7be60b7ecbab0e260776
chunyang-wen/dynet,clab/cnn,shuheik/dynet,shuheik/dynet,danielhers/dynet,danielhers/dynet,chunyang-wen/dynet,clab/cnn,shuheik/dynet,shuheik/dynet,danielhers/dynet,clab/dynet,clab/dynet,shuheik/dynet,clab/dynet,clab/cnn,danielhers/dynet,danielhers/dynet,danielhers/dynet,xunzhang/dynet,xunzhang/dynet,chunyang-wen/dynet,clab/dynet,clab/dynet,chunyang-wen/dynet,clab/dynet,xunzhang/dynet,clab/dynet,danielhers/dynet,shuheik/dynet,xunzhang/dynet,shuheik/dynet