Load Graph modules only if available

Netdisco/Changes

@@ -1,3 +1,9 @@
+2.028011 - 2014-07-22
+
+  [BUG FIXES]
+
+  * Load Graph modules only if available
+
 2.028010 - 2014-07-22
 
   [NEW FEATURES]

Netdisco/bin/netdisco-do

@@ -82,7 +82,8 @@ if (!length $action) {
   with 'App::Netdisco::Daemon::Worker::Interactive::DeviceActions';
   with 'App::Netdisco::Daemon::Worker::Interactive::PortActions';
 
-  use App::Netdisco::Util::Graph ();
+  use Module::Load ();
+  eval { Module::Load::load 'App::Netdisco::Util::Graph' };
   sub graph {
     App::Netdisco::Util::Graph::graph();
     return ('done', 'Generated graph data.');