reorganise symlinkoption

tiramisu/option/option.py

@@ -525,7 +525,7 @@ class Option(OnlyOption):
             if opt.impl_is_submulti():
                 raise ConfigError(_('cannot add consistency with submulti option'))
             if not isinstance(opt, Option):
-                raise ConfigError(_('consistency must be set with an option'))
+                raise ConfigError(_('consistency must be set with an option, not {}').format(opt))
             if opt._is_subdyn():
                 if dynod is None:
                     raise ConfigError(_('almost one option in consistency is '

tiramisu/option/syndynoptiondescription.py

@@ -73,9 +73,6 @@ class SynDynOptionDescription(object):
             subpath += '.'
         return subpath + self.impl_getname()
 
-    def impl_getopt(self):
-        return self._opt
-
     def getmaster(self):
         master = self._opt.getmaster()
         return DynSymLinkOption(master,