v3.5.0-alpha1

First step migration to eZ 5 Symfony stack.

Following items have been migrated:

• Pagelayout and related templates (using legacy fallback from time to time)
• Configuration to fit eZ 5 configuration

Content views are still all handled by the legacy stack (old tpl in the legacy extension). We however take advantage of performance improvement with HttpCache as we now go through the built-in ViewController