window: update_view when the property changes

Update the value of the internal holder of the property
window: update date on view on binding creation

Ensure the views has events widgets in it for the first time the user
clicks on it.
misc: fix styling issues and gcc warnings

Update code style
week-view: add subscriber range update

Remove unneeded GcalView deprecated method.
Hook event widget activation
week-view: rename internal method

Note: The body of the method was added by mistake on the previous
commit. This commit make the code build again.
week-view: fix unref of not added widget

This works in conjunction with code implemented in GcalSubscriber where
the ownership of the event widget passes into the container, so the
container is free to delete it in case it does not fit into the range
represented by the view.