Fix URL param overrides upon rendering

Before, we used setParams() instead of with() to populate the parameters
which is especially problematic with imported nodes where the config
paramter got overriden for every subsequent node.

fixes #228

library/Businessprocess/Renderer/Renderer.php

@@ -214,7 +214,8 @@ abstract class Renderer extends HtmlDocument
             $paths = $node->getPaths();
         }
 
-        $url = $this->getUrl()->setParams([
+        $url = clone $this->getUrl();
+        $url->setParams([
             'config'    => $node->getBpConfig()->getName(),
             'node'      => $name
         ]);

library/Businessprocess/Renderer/TileRenderer.php

@@ -30,7 +30,7 @@ class TileRenderer extends Renderer
         if ($this->wantsRootNodes()) {
             $nodesDiv->getAttributes()->add(
                 'data-action-url',
-                $this->getUrl()->setParams(['config' => $bp->getName()])->getAbsoluteUrl()
+                $this->getUrl()->with(['config' => $bp->getName()])->getAbsoluteUrl()
             );
         } else {
             $nodeName = $this->parent instanceof ImportedNode
@@ -39,7 +39,7 @@ class TileRenderer extends Renderer
             $nodesDiv->getAttributes()
                 ->add('data-node-name', $nodeName)
                 ->add('data-action-url', $this->getUrl()
-                    ->setParams([
+                    ->with([
                         'config'    => $this->parent->getBpConfig()->getName(),
                         'node'      => $nodeName
                     ])

library/Businessprocess/Renderer/TreeRenderer.php

@@ -42,7 +42,7 @@ class TreeRenderer extends Renderer
         if ($this->wantsRootNodes()) {
             $tree->getAttributes()->add(
                 'data-action-url',
-                $this->getUrl()->setParams(['config' => $bp->getName()])->getAbsoluteUrl()
+                $this->getUrl()->with(['config' => $bp->getName()])->getAbsoluteUrl()
             );
         } else {
             $nodeName = $this->parent instanceof ImportedNode
@@ -51,7 +51,7 @@ class TreeRenderer extends Renderer
             $tree->getAttributes()
                 ->add('data-node-name', $nodeName)
                 ->add('data-action-url', $this->getUrl()
-                    ->setParams([
+                    ->with([
                         'config'    => $this->parent->getBpConfig()->getName(),
                         'node'      => $nodeName
                     ])
@@ -203,7 +203,7 @@ class TreeRenderer extends Renderer
             ]),
             'data-csrf-token'               => CsrfToken::generate(),
             'data-action-url'               => $this->getUrl()
-                ->setParams([
+                ->with([
                     'config'    => $node->getBpConfig()->getName(),
                     'node'      => $node instanceof ImportedNode
                         ? $node->getNodeName()