[Building Sakai] Question about bean aliases in 2.7.x

[Jim Eng]

In past sakai releases, one could supply a bean alias in a properties file like this:

org.sakaiproject.authz.api.GroupProvider=org.sakaiproject.authz.api.GroupProviderUnivOfMich

With that line in local.properties or sakai.properties, "org.sakaiproject.authz.api.GroupProvider" becomes an alias for "org.sakaiproject.authz.api.GroupProviderUnivOfMich" any place that a bean is referenced as "org.sakaiproject.authz.api.GroupProvider".  

That doesn't seem to work in sakai 2.7.x.  Does anyone know why?  Is this a change in sakai code? Or something in spring?  Or a side-effect of switching to JVM 1.6?  

Should this be considered a bug?  

Thanks.

Jim