Changes to fix the following bugs:
    Bug 228104: greater than 2 legged cluster mirrors do not down ...
    Bug 228056: lvconvert should give warning if we don't support ...
    
    When converting from 3-way to 2-way mirror, the UUID for the mirror
    stays the same.  This creates conflicting entries in the cluster
    logging code.  I've added an additional identifier to allow for
    unique identification in these cases.