This updates the systemd config to add VGW_IAM_LDAP_USER_ID_ATR
amd VGW_IAM_LDAP_GROUP_ID_ATR env var options that were already
in the cli config.
Fixes#733
This adds the ability to treat symlinks to directories at the top
level gateway directory as buckets the same as normal directories.
This could be a potential security issue allowing traversal into
other filesystems within the system, so is defaulted to off. This
can be enabled when specifically needed for both posix and scoutfs
backend systems.
Fixes#644
