v0.5.3 Patch Update

This is a patch release mainly for supporting CUDA 11.0. Now DGL supports CUDA 11.0 and PyTorch 1.7 on Linux/Windows/Mac.

Other fixes include:

• Performance fix of graph batching. Affect the dgl.batch API.
• Speedup on graph readout. Affect all APIs under dgl.readout.
• Speedup in CPU SpMM with sum reducer.
• Performance optimization that removes redundant copies between CPU and GPU.
• Fix segment_reduce() ignoring tailing 0 segments.
• Fix a crash bug due to unfound attribute.
• Performance optimization in COO-CSR conversion.
• Parallelization in heterogeneous graph format conversion.
• Fix a bug to enable distributed training of RGCN with CPU.
• Numerous documentation fixes.

New examples:

• Sparse embedding for GATNE-T for large graphs.
• LINE.
• SIGN for OGB.

The Chinese user guide has been released for chapter 1 to 4. Further chapters will be released soon.

Full release note: https://github.com/dmlc/dgl/releases/tag/0.5.3