Adjust dca files and callbacks to work with toolkit v2.

src/Netzmacht/Contao/Leaflet/Alias/UnderscoreFilter.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * @package    netzmacht
+ * @author     David Molineus <david.molineus@netzmacht.de>
+ * @copyright  2016 netzmacht David Molineus. All rights reserved.
+ * @filesource
+ *
+ */
+
+namespace Netzmacht\Contao\Leaflet\Alias;
+
+use Netzmacht\Contao\Toolkit\Data\Alias\Filter;
+
+/**
+ * Class UnderscoreFilter
+ *
+ * @package Netzmacht\Contao\Leaflet\Alias
+ */
+class UnderscoreFilter extends Filter\AbstractFilter
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function repeatUntilValid()
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function apply($model, $value, $separator)
+    {
+        return str_replace('-', '_', $value);
+    }
+}