Add IsLocalCluster() predicate.

apt/APT_Aggregate.pm.in

@@ -43,6 +43,7 @@ use overload ('""' => 'Stringify');
 my $TB		  = "@prefix@";
 my $TBOPS         = "@TBOPSEMAIL@";
 my $OURDOMAIN     = "@OURDOMAIN@";
+my $MYURN	  = "urn:publicid:IDN+${OURDOMAIN}+authority+cm";
 
 # Protos
 sub STATUS($$;$);
@@ -124,6 +125,13 @@ sub DESTROY {
     $self->{'AGGREGATE'} = undef;
 }
 
+sub IsLocalCluster($)
+{
+    my ($self) = @_;
+
+    return ($self->urn() eq $MYURN ? 1 : 0);
+}
+
 #
 # Refresh a class instance by reloading from the DB.
 #