Excel export extension available
New twig function 'supported_export_extensions'
New dependency on phpoffice/phpexcel
seperate response from document creation
make supported extensions method static
Merge branch 'feature/exportXls' into develop

* feature/exportXls:
  make supported extensions method static
  seperate response from document creation
  Excel export extension available New twig function 'supported_export_extensions' New dependency on phpoffice/phpexcel
fix dependency on phpexcel for bundles-standard-edition
Merge branch 'master' of https://github.com/Devolicious/KunstmaanAdminListBundle

* 'master' of https://github.com/Devolicious/KunstmaanAdminListBundle:
  Extend from add_or_edit.html.twig I should be able to only overwrite the form