YANG Action (RFC 7950 Section 7.15)

See [Support for "action" statement](https://github.com/clicon/clixon/issues/101)

include/clixon_custom.h

@@ -163,3 +163,20 @@
  * If not set, client will exit
  */
 #define PROTO_RESTART_RECONNECT
+
+/*! Text output keys as identifiers instead of ordinary leafs
+ * That is, given list "list" with key value "a", if set, the output of show config or save
+ * as text command is:
+ *    list a { 
+ *       val 42; 
+ *    }
+ * If not set, the output is:
+ *    list { 
+ *       keyname a; 
+ *       val 42; 
+ *    }
+ * The TEXT parser (ie load) accepts both formats.
+ */
+#define TEXT_LIST_KEYS
+
+