Add implementation of os2web_subscription when meetings are updated to "Referat"
Add os2web subscription form to the button of dagsorden search page.
Add implementation to be able to subscribe to certain committees.

Some cleanup.
Show list of categories to subscribe to, on overview page.
A better us of titles.
Add the subscription type into the array index.
Only send to queue if younger than xx days. Adds a setting in os2web subscription.
Move setting field into correct hook.
Merge branch 'feature/subscription'