Added support for MCO named parameters.

Created by: stefanoborini

Introduces the MCO Parameter classes with support for naming

force_bdss/mco/parameters/base_mco_parameter.py

+from traits.api import HasStrictTraits, String, Instance
+
+from force_bdss.mco.parameters.base_mco_parameter_factory import \
+    BaseMCOParameterFactory
+
+
+class BaseMCOParameter(HasStrictTraits):
+    """The base class of all MCO Parameter models.
+    Must be reimplemented by specific classes handling the specific parameter
+    that MCOs understand.
+    """
+
+    #: The generating factory. Used to retrieve the ID at serialization.
+    factory = Instance(BaseMCOParameterFactory, visible=False, transient=True)
+
+    #: A user defined name for the parameter
+    value_name = String()
+
+    #: A CUBA key describing the type of the parameter
+    value_type = String()
+
+    def __init__(self, factory, *args, **kwargs):
+        self.factory = factory
+        super(BaseMCOParameter, self).__init__(*args, **kwargs)