Add a new html_attributes to work with angular.js

Angular JS require to add a new attribute ng-app to the html tag.

This new block allow us to add it, for example :

{% block html_attributes %}ng-app="PrestaCMS.Page"{% endblock %}
Add class="no-js" directly in the block
Merge pull request #1639 from nicolas-bastien/patch-1

Add a new html_attributes to work with angular.js
Fix ACL editor
Merge pull request #1642 from dunglas/fix-acl-editor

Fix ACL editor
Added DatagridTest
Improved ModelToIdTransformerTest
Merge pull request #1646 from pulzarraider/transformer_test1

Improved ModelToIdTransformerTest
Update LICENSE

Year range updated
Merge pull request #1647 from peterkokot/patch-1

Update LICENSE
Merge pull request #1644 from pulzarraider/datagrid_test2

Added DatagridTest
Change ambiguous inline action "view" to "show".

Deleted list__action_view.html.twig template, added deprecated info in ListMapper.
Merge pull request #1622 from pulzarraider/inline_action_show

Change ambiguous list inline action "view" to "show".
Merge branch 'sonata/master'