feat(modeling): add reconnect rule

lib/features/rules/BpmnRules.js

@@ -105,6 +105,15 @@ BpmnRules.prototype.init = function() {
     return canConnect(source, target, connection);
   });
 
+  this.addRule('connection.reconnect', function(context) {
+
+    var connection = context.connection,
+        source = context.source,
+        target = context.target;
+
+    return canConnect(source, target, connection);
+  });
+
   this.addRule('connection.updateWaypoints', function(context) {
     return {
       type: context.connection.type