babeld: justify "running-config" meaning in CLI

The primary focus of this commit is to make "show running-config"
command display more current configuration, including some of the bits
previously seen in the output of "show babel running-config". Besides
that, the following commands were renamed for consistency with the
syntax of other components:

"debug *" to "debug babel *" (and moved to top level)
"show babel running-config" to "show babel parameters"

* babel_interface.c
  * show_babel_running_config(): rename to show_babel_parameters(),
    update syntax pattern, don't call show_babeld_configuration()
  * babel_if_init(): update respectively
  * babel_enable_if_config_write(): new VTY helper for static
    babel_enable_if
* babel_interface.h: add extern declaration
* babel_main.c: unset all debug options by default
  * show_babel_main_configuration(): remove debug options decoder
* babel_zebra.c
  * babel_debug(): rename to debug_babel(), update syntax pattern
  * no_babel_debug(): rename to no_debug_babel(), update syntax pattern
  * babelz_zebra_init(): update respectively
  * debug_babel_config_write() new VTY helper for static debug_type
* babel_zebra.h: add extern declaration
* babeld.c
  * babel_config_write(): add the code to output "debug babel *",
    "router babel", "redistribute *" and "network *" statements
  * show_babeld_configuration(): dismiss
* babeld.h: remove extern declaration
* babeld.texi: update for renamed commands
* babeld.conf.sample: idem, add debug statements block
diff --git a/babeld/babeld.c b/babeld/babeld.c
index 07dd92a..9fea2e1 100644
--- a/babeld/babeld.c
+++ b/babeld/babeld.c
@@ -59,6 +59,7 @@
 #include "message.h"
 #include "resend.h"
 #include "babel_filter.h"
+#include "babel_zebra.h"
 
 
 static int babel_init_routing_process(struct thread *thread);
@@ -92,7 +93,26 @@
 static int
 babel_config_write (struct vty *vty)
 {
-    return 0;
+    int lines = 0;
+    int i;
+
+    /* list enabled debug modes */
+    lines += debug_babel_config_write (vty);
+
+    if (!babel_routing_process)
+        return lines;
+    vty_out (vty, "router babel%s", VTY_NEWLINE);
+    /* list enabled interfaces */
+    lines = 1 + babel_enable_if_config_write (vty);
+    /* list redistributed protocols */
+    for (i = 0; i < ZEBRA_ROUTE_MAX; i++)
+        if (i != zclient->redist_default && zclient->redist[i])
+        {
+            vty_out (vty, " redistribute %s%s", zebra_route_string (i), VTY_NEWLINE);
+            lines++;
+        }
+
+    return lines;
 }
 
 
@@ -701,9 +721,3 @@
     return 0;
 }
 
-void
-show_babeld_configuration (struct vty *vty)
-{
-    vty_out(vty, "babeld running process %s.%s",
-            babel_routing_process ? "enable" : "disable", VTY_NEWLINE);
-}