Add ngFsCouplePortrait directive for use in the new add flow.

@lambertsteven Can you take a look at this and merge it? This is the new ngFsCouplePortrait directive. There's also a pull request in fs-styles for the matching styles. Thanks.
I'm adding a separate watch for the husband and the wife. It seems that angular 1.3 has a $watchCollection function that would work in this case, but we're still on 1.2.