Bug 982029 - [MMS/SMS] Display email in SMS/MMS Threads r=Steve

https://bugzilla.mozilla.org/show_bug.cgi?id=982029
so, you can't do this, because this won't match correctly phone number.

Here is what you need to do in my opinion:
* check if filterValue is an email and Settings.supportEmailRecipient is true
* if it's not an email, call findByPhoneNumber
* if it's an email, call a new function findExactByEmail

findExactByEmail will simply call findBy using ['email'] and the operation 'equals'. In the future you'll be able to add the facebook search if necessary.