feature #4264 [#4003] A few more form_themes config changes (weaverryan)

This PR was merged into the master branch.

Discussion
----------

[#4003] A few more form_themes config changes

| Q             | A
| ------------- | ---
| Doc fix?      | #4003
| New docs?     | not, but finishing an earlier change
| Applies to    | >= 2.6
| Fixed tickets | -

Hi guys!

This follows #4003 - I think I found a few other spots that needed to be updated.

Thanks!

Commits
-------

695cb20 [#4003] A few more form_themes config changes

Author: weaverryan

book/forms.rst

@@ -1580,9 +1580,8 @@ file:
 
         # app/config/config.yml
         twig:
-            form:
-                resources:
-                    - 'AcmeTaskBundle:Form:fields.html.twig'
+            form_themes:
+                - 'AcmeTaskBundle:Form:fields.html.twig'
             # ...
 
     .. code-block:: xml
@@ -1596,9 +1595,7 @@ file:
                 http://symfony.com/schema/dic/twig http://symfony.com/schema/dic/twig/twig-1.0.xsd">
 
             <twig:config>
-                <twig:form>
-                    <twig:resource>AcmeTaskBundle:Form:fields.html.twig</twig:resource>
-                </twig:form>
+                <twig:theme>AcmeTaskBundle:Form:fields.html.twig</twig:theme>
                 <!-- ... -->
             </twig:config>
         </container>
@@ -1607,10 +1604,8 @@ file:
 
         // app/config/config.php
         $container->loadFromExtension('twig', array(
-            'form' => array(
-                'resources' => array(
-                    'AcmeTaskBundle:Form:fields.html.twig',
-                ),
+            'form_themes' => array(
+                'AcmeTaskBundle:Form:fields.html.twig',
             ),
             // ...
         ));

cookbook/form/create_custom_field_type.rst

@@ -159,27 +159,22 @@ link for details), create a ``gender_widget`` block to handle this:
 
             # app/config/config.yml
             twig:
-                form:
-                    resources:
-                        - 'AcmeDemoBundle:Form:fields.html.twig'
+                form_themes:
+                    - 'AcmeDemoBundle:Form:fields.html.twig'
 
         .. code-block:: xml
 
             <!-- app/config/config.xml -->
             <twig:config>
-                <twig:form>
-                    <twig:resource>AcmeDemoBundle:Form:fields.html.twig</twig:resource>
-                </twig:form>
+                <twig:form-theme>AcmeDemoBundle:Form:fields.html.twig</twig:form-theme>
             </twig:config>
 
         .. code-block:: php
 
             // app/config/config.php
             $container->loadFromExtension('twig', array(
-                'form' => array(
-                    'resources' => array(
-                        'AcmeDemoBundle:Form:fields.html.twig',
-                    ),
+                'form_themes' => array(
+                    'AcmeDemoBundle:Form:fields.html.twig',
                 ),
             ));