euscan/handlers: rework handlers, better remote-id + watch support

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>

bin/euscan

@@ -298,11 +298,16 @@ def main():
             exit_helper(1)
 
         except Exception as err:
+            import traceback
+            print ('-'*60)
+            traceback.print_exc(file=sys.stderr)
+            print ('-'*60)
+
             output.eerror('%s: %s' % (query, str(err)))
             exit_helper(1)
 
         if not ret and not CONFIG['quiet']:
-            output.ewarn(
+            output.einfo(
                 "Didn't find any new version, check package's homepage " +
                 "for more informations"
             )