Unify gdb printf functions

Now that filtered and unfiltered output can be treated identically, we
can unify the printf family of functions.  This is done under the name
"gdb_printf".  Most of this patch was written by script.

gdb/inf-loop.c

@@ -85,7 +85,7 @@ inferior_event_handler (enum inferior_event_type event_type)
       break;
 
     default:
-      fprintf_unfiltered (gdb_stderr, _("Event type not recognized.\n"));
+      gdb_printf (gdb_stderr, _("Event type not recognized.\n"));
       break;
     }
 }