add some tests for dynoptiondescription + correction

tiramisu/setting.py

@@ -484,8 +484,11 @@ class Settings(object):
                 exps, action, inverse, transitive, same_action, operator = require
                 breaked = False
                 for option, expected in exps:
+                    if option.issubdyn():
+                        option = option.impl_get_dynoption(option_bag.option._rootpath,
+                                                           option_bag.option.impl_getsuffix())
                     reqpath = option.impl_getpath(context)
-                    #FIXME c'est un peu tard !
+                    #FIXME too later!
                     if reqpath.startswith(option_bag.path + '.'):
                         raise RequirementError(_("malformed requirements "
                                                  "imbrication detected for option:"