properties option in consistencies are now allowed

Conflicts:
	tiramisu/option.py (PortOption._validate): Strange try/except
	removed.

tiramisu/option.py

@@ -367,7 +367,8 @@ class Option(BaseOption):
                 #if context, calculate value, otherwise get default value
                 if context is not None:
                     opt_value = context._getattr(
-                        descr.impl_get_path_by_opt(opt), validate=False)
+                        descr.impl_get_path_by_opt(opt), validate=False,
+                        force_permissive=True)
                 else:
                     opt_value = opt.impl_getdefault()