bugfix: allow generating graphs of pipelines with a dot in their name

modules/Bio/EnsEMBL/Hive/Utils/Graph.pm

@@ -329,6 +329,7 @@ sub _add_pipeline_label {
     my $node_fontname       = $self->config_get('Node', 'Details', 'Font');
     my $pipeline_label      = $pipeline->display_name;
     my $pipelabel_node_name = 'pipelabel_'.$pipeline->hive_pipeline_name;
+       $pipelabel_node_name =~ s/\./_/g;
 
     $self->graph()->add_node( $pipelabel_node_name,
         shape     => 'plaintext',

modules/Bio/EnsEMBL/Hive/Utils/GraphViz.pm

@@ -123,7 +123,7 @@ sub display_subgraph {
 
     my $prefix = "\t" x $depth;
     my  $text = '';
-        $text .= $prefix . "subgraph cluster_${cluster_name} {\n";
+        $text .= $prefix . "subgraph \"cluster_${cluster_name}\" {\n";
 
         # uncomment the following line to see the cluster names:
 #     $text .= $prefix . "\tlabel=\"$cluster_name\";\n";