Add libuserdefs and use in cmd/{oamuser,passwd}

@@ -96,10 +96,37 @@
         { USERATTR_AUDIT_FLAGS_KW, check_auditflags, auditflags },
 };
 
 #define NKEYS   (sizeof (keys)/sizeof (ua_key_t))
 
+/* Import default keys for ordinary useradd */
+void
+import_def(struct userdefs *ud)
+{
+        int i;
+
+        /* Don't import the user type (skip i = 0) */
+        for (i = 1; i < NKEYS; i++) {
+                if (keys[i].newvalue == NULL)
+                        keys[i].newvalue =
+                            userdef_get_by_uakey(ud, keys[i].key);
+        }
+}
+
+/* Export command line keys to defaults for useradd -D */
+void
+update_def(struct userdefs *ud)
+{
+        int i;
+
+        for (i = 0; i < NKEYS; i++) {
+                if (keys[i].newvalue != NULL)
+                        userdef_set_by_uakey(ud, keys[i].key,
+                            keys[i].newvalue);
+        }
+}
+
 /*
  * Change a key, there are three different call sequences:
  *
  *              key, value      - key with option letter, value.
  *              NULL, value     - -K key=value option.