added widget id to dcbe_general_field template and contaowidgetmanager
code style
added exteded version conditions to datepicker
Merge tag '2.0.0-alpha5' into develop

Version 2.0.0-alpha5
Make DataContainerInterface extend EnvironmentAwareInterface.
Also apply parent filter in tree view if defined.
Drop BaseView::dispatchEvent.
Code style.
Code style.
Code style.
Add 3.3 as allowed failure to composer.json
Preserve the model id for option callbacks in the widget manager.
Merge pull request #7 from cogizz/fix/contao-date-picker

DatePicker funktioniert nicht.
Merge branch 'release/2.0.0-alpha6'