Reword approval mail to avoid have it sound as if people MUST use

the link to join.  Thus after they inevitable lose the URL, they
won't be deterred from inviting people to join.

www/approveproject.php3

@@ -221,9 +221,10 @@ elseif (strcmp($approval, "approve") == 0) {
     TBMAIL("$headname '$headuid' <$headuid_email>",
          "Project '$pid' Approval",
          "\n".
-	 "This message is to notify you that your project $pid\n".
-	 "has been approved. Please save this link so that you can send it\n".
-	 "to people you wish to have join your project:\n".
+	 "This message is to notify you that your project '$pid'\n".
+	 "has been approved.  We recommend that you save this link so that\n".
+	 "you can send it to people you wish to have join your project.\n".
+	 "Otherwise, tell them to go to ${TBBASE} and join it.\n".
 	 "\n".
 	 "    ${TBBASE}/joinproject.php3?target_pid=$pid\n".
          "\n".