GUACAMOLE-793: Add Docker environment variables for group-related CAS properties.
GUACAMOLE-793: Add Docker environment variables for group-related CAS properties.

glyptodon/guacamole-client,glyptodon/guacamole-client,glyptodon/guacamole-client,glyptodon/guacamole-client,glyptodon/guacamole-client