Honoree should never be same as donor

If you submit a contribution form in honor of someone, that contact created should never be yourself. In 4.6 and 4.7, if the honoree's information matches the donor's, the donor is updated with the honoree's information and the resulting contribution has a soft credit to the donor.

This is separate from CRM-15813 but can present itself similarly.

This becomes a problem because the default honoree profile includes email address, but many people donating in honor of someone think the form would email that person, so they enter their own address.