"[D]etermine whether the FMLA applies to you. If so, you should: [1] Train your leave administrators and supervisors on the new rule.... [2] Review and amend your FMLA policy and procedures, as well as all FMLA-related forms and notices, to the extent that they specifically define the term 'spouse' in a way that does not account for the new rule.... [3] [T]he FMLA does not protect civil unions or domestic partnerships, so employers are well advised to determine whether FMLA applies in any particular situation.... [State] laws may differ on their definitions of same-sex marriage, civil unions and domestic partnerships, and may offer different leave rights depending on the protected category."