Revert some of the changes done in
a7324c5f15effe5d2b78992fc7b829b29152a7f9. Continue supporting the
environment variable "HUGO_ENV" which doesn't affect Hugo while still
supporting the new, official ways of setting the environment.
<body> will however get a class named by the official environment only
since it would be confusing to add both a "development" class and a
"production" class at the same time if the site is rendered using this
command for instance:
$ HUGO_ENV=production hugo server
The Ananke theme got environment support before Hugo did and when Hugo
added it in version 0.53 it was in a slightly different way. Running
"hugo server" will set the environment to "development" and running just
"hugo" will set it to "production". It can be overridden by OS
environment variable "HUGO_ENVIRONMENT" (note, not "HUGO_ENV") or by
using the --environment option.
Use "hugo.Environment" to detect environment instead and update the
README.
