Updates to support improvements to che-server Docker container

[TylerJewell]

The Che Dockerfile has been improved to remove the number of volume mounts that are required. Also, certain environment variables have been simplified. This includes a series of changes to reflect these improvements. We need to update some of the docs as the following environment variables have changed.

CHE_DATA_FOLDER --> CHE_DATA
CHE_CONF_FOLDER --> CHE_CONF
CHE_LOCAL_BINARY --> CHE_ASSEMBLY

If a user does not provide the CHE_DATA folder, Che will start with writing all files into /home/user/che and they will not exist if you restart Che on Windows.