feature #1204 Add form type support in FormTrait for flexibility (lokhman)

This PR was submitted for the 1.3 branch but it was merged into the 2.0.x-dev branch instead (closes #1204).

Discussion
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Add form type support in FormTrait for flexibility

Set parameter to the end for backwards compatibility, ideally make it first in the future release.

Commits
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3ffe0c72 Add form type support in FormTrait for flexibility

src/Silex/Application/FormTrait.php

@@ -25,11 +25,12 @@ trait FormTrait
      *
      * @param mixed                    $data    The initial data for the form
      * @param array                    $options Options for the form
+     * @param string|FormTypeInterface $type    Type of the form
      *
      * @return FormBuilder
      */
-    public function form($data = null, array $options = array())
+    public function form($data = null, array $options = array(), $type = 'form')
     {
-        return $this['form.factory']->createBuilder('form', $data, $options);
+        return $this['form.factory']->createBuilder($type, $data, $options);
     }
 }