Get the user environments defined recursively within the given user environments
get_user_environments_in_user_envs_recursively(env_user_names, envir)names of the user environments where the recursive search is carried out.
user environment where ALL environments in env_user_names live,
or NULL if those environments may live in different environments. In this case
the names of the environment where each env_user_names live is taken
from its names attribute.
a list containing the following elements:
fullnames the full names of the environments
addresses the addresses of the environments
locationaddresses the addresses of the locations of the environments