Bug 1023764 - [Loop] Keep Contacts Info updated. r=borjasalguero, jaoo

Here the logic should be something like 
`if (reason === 'remove') {`
` _removeContact(entry, contactId, i == 0);`
`return;`
`}`
`_updateContact(entry, contact)`

So in this case, if an update is needed we will use `contactId` and `identities` within `_updateContact` in order to decide if an update is needed and which fields are going to be updated.