Code for "High-Resolution Representations for Labeling Pixels and Regions" (#610)

* support HRNet

* add zip

* remove zip files

* remove zip datasets in config

* modify format and shorten lines

* fix line to long

* support conv_cfg and update conv layer

* revise the backbone network and neck

* update format and pretrained mode

* fix flake8 error

* update modules following review suggestions

* revert some changes for adapting to pretrained models

* update hrnet and hrfpn

* remove unused import

* remove unused import

* finish testing

* change pretrained model link to open-mmlab

* fix docstring and convert models

* update README and model links

* modify configs and README

* support loss evaluator

* update model urls

* format hrnet.py

* format hrfpn.py

* add 20e for cascade config