* WIP: using object system for graph * c++ side refactoring done; compiled * remove stale apis * fix bug in DGLGraphCreate; passed test_graph.py * fix bug in python modify; passed utest for pytorch/cpu * fix lint * address comments
* WIP: import tvm runtime node system * WIP: object system * containers * tested basic container composition * tested custom object * fix setattr bug * tested object container return * fix lint * some comments about get/set state * fix lint * fix lint * update cython * fix cython * ffi doc * fix doc
Minjie Wang