Problem: mandatory keyword restriction is forced

[mehdisadeghi]

This PR disables mandatory keyword restriction on data property of CUDS classes. In order to have restriction, one must do it manually:

RestrictedDataContainer = create_data_container(Material.supported_parameters())
rdc = RestrictedDataContainer()
rdc[CUBA.NAME] = 'myname'
m1 = Material(data=rdc)
m2 = Material()
m1.data[CUBA.MASS] = 1.0 # Not allowed
m2.data[CUBA.MASS] = 1.0 #Allowed by default

Solution: disable it.

[mehdisadeghi]

Related PR: simphony/simphony-common#293