* Changed debug levels in clicon_debug() to be based on maskable flags

* Added flag names: `CLIXON_DBG_*`
  * Added maskable flags that can be combined when debugging:
    * `DEFAULT` = 1: Basic debug message, espcially initialization
    * `MSG` = 2: Input and output packets, read datastore
    * `DETAIL` = 4: Details: message dump in hex, xpath parse trees, etc
    * `EXTRA` = 8: Extra detailed logs
* Test: some errors in yang-lib where content-id was in wrong place

apps/cli/cli_main.c

@@ -780,8 +780,7 @@ main(int    argc,
     if (logclisyntax)
         cli_logsyntax_set(h, logclisyntax);
 
-    if (dbg)
-        clicon_option_dump(h, dbg);
+    clicon_option_dump(h, 1);
     
     /* Join rest of argv to a single command */
     restarg = clicon_strjoin(argc, argv, " ");