heimdal packaging

[Orion Poplawski]

I'm starting to take a look at the heimdal package review: 
https://bugzilla.redhat.com/show_bug.cgi?id=613001

heimdal is an alternative kerberos implementation to MIT-Kerberos.  I'm 
assuming we will want to explore the use of alternative to allow coexistence.

One trick part it for EL6 support.  I'm assuming that there really is no way 
we'll get alternatives support into the RHEL6 krb5 package.  In that case is 
it acceptable to fall back to the /usr/heimdal/ prefix for the package?