AML does not allow password changes when there are multiple instances of an email address

When the same email address is used on multiple realms on a stack, the password reset feature in the UI does not work as that feature does not see that an email address belongs to a specific realm. The user sees a 'Cannot reset the password at this time' message. In the tomcat log, you see:

ID: 71920
Response-Code: 500
Content-Type: text/plain;charset=UTF-8;version=2.8.5
Headers:

{Date=[Fri, 13 Nov 2015 18:48:14 GMT], X-AML-API-ID=[9736f39e-01e3-442f-84a0-e0cd72111601], Expires=[-1], Cache-Control=[no-cache], Pragma=[no-cache]}

Payload: Multiple users found with email 'ben.gibson@admaxlocal.com'

With the new multi-realm support coming in Mercury we need to be able to support password resets for a user that exists in multiple realms in the same stack.