useradd: support many other groups; try to grp_name if name doesn't exist.

windows/scripts/useradd

@@ -150,10 +150,11 @@ function add_member_to_group()
 {
   local name=$1
   local grpname=$2
+  net localgroup $grpname > /dev/null 2>&1 || grpname="grp_$grpname"
+  net localgroup $grpname > /dev/null 2>&1 || return 1
   if ! net localgroup $grpname | grep -q -e "^$name$" ; then
       net localgroup $grpname $name /add
   fi
-  net localgroup $grpname | grep -q -e "^$name$"
 } # === End of add_member_to_group() === #
 
 while getopts "Dd:g:G:p:s:r" opt ; do
@@ -165,7 +166,7 @@ while getopts "Dd:g:G:p:s:r" opt ; do
             USER_INIT_GROUP=$OPTARG
             ;;
         G)
-            USER_OTHER_GROUP=$OPTARG
+            USER_OTHER_GROUP="$USER_OTHER_GROUP $OPTARG"
             ;;
         p)
             USER_PASSWORD=$OPTARG