Use RouterInterface instead of Router for compatibility with Symfony CMF ChainRouter
Provide twig forum global by using a twig extension

Setting the twig global from the bundle class's boot() method causes weird errors for some console scripts like doctrine:phpcr:init:dbal and doctrine:phpcr:repository:init
Remove broken data fixtures
Merge branch 'pr/twig_globals'
Merge branch 'pr/remove_fixtures'