Register multiple dimensions on the cube.

        .. code-block:: python

            cube.register_dimensions([
                {'name' : 'ntime', 'global_size' : 10,
                'lower_extent' : 2, 'upper_extent' : 7 },
                {'name' : 'na', 'global_size' : 3,
                'lower_extent' : 2, 'upper_extent' : 7 },
            ])


        Parameters
        ----------
        dims : list or dict
            A list or dictionary of dimensions

def register_dimensions(self, dims):
        """
        Register multiple dimensions on the cube.

        .. code-block:: python

            cube.register_dimensions([
                {'name' : 'ntime', 'global_size' : 10,
                'lower_extent' : 2, 'upper_extent' : 7 },
                {'name' : 'na', 'global_size' : 3,
                'lower_extent' : 2, 'upper_extent' : 7 },
            ])


        Parameters
        ----------
        dims : list or dict
            A list or dictionary of dimensions

        """

        if isinstance(dims, collections.Mapping):
            dims = dims.itervalues()

        for dim in dims:
            self.register_dimension(dim.name, dim)