GitLab

Pattern from: https://packaging.python.org/guides/single-sourcing-package-version/

* Add documentation for transforms

* document and remove unused imports in mnist.py

* document lsun, mscoco datasets

* rest of the datasets documented

* Clean up the documentation in other functions

* Add links for datasets

* Add more documentation

* pep8 fix

It can be enabled by calling torchvision.set_image_backend('accimage')