Action to add a sepa mandate (recurring to contribution to a membership)

Add a sepa mandate to a membership. A sepa mandate is a recurring contribution in the Project 60 Sepa Extension.

So we need the following:

Add parameter for Contribution Recur to actions Create and Update membership. Ad the contribution_recur_id is a field on the membership record
In addition we need a separate action for linking a Contribution recur to a membership
And we need a separate action for removing a contribution recur from a membership