* data preprocessing for rgcn
* edge subgraph
* WIP: RGCN
* use edge feature in spmv
* fix bugs
* match AIFB accuracy
* match mutag accuracy
* avoid materializing in featureless case
* remove untouched nodes and relabel nodes
* fix python list concatenate overhead
* sparsely store edge types
* refactor entity classify code for clean link prediction implementation
* further refactor code
* refactoring
* rgcn block decompose layers
* link predict dataset
* link predict model and eval code
* dropout, self-loop, regularization, etc, plus bug fixes
* update to new api
* dataset update
* bugs, WIP, need to impl early stopping and filtered metrics
* instruction to run, and minor
* group conv and early stop
* clean slow code
* some code comments
* use new api in model code
* change data preprocessing
* entity classify model
* WIP
* move dgl graph out of model
* hot fix for extract zip
* fix link predict model
* use latest dgl apis
* still have memory issue...
* bug fix and move inference to cpu
* move rgcn data processing to contrib
* th.allclose -> U.allclose
* minor change in readme
* fix memory issue in entity classify
* fix and testing code for link predict
* fix entity classify
* clean up
* fix comments
* revert erroneous git merge changes
* code clean up and more comments
* minor
* dependent package version
Lingfan Yu