[IMP] [FIX] website_forum: cleaned and improved the management of available actions based on the user's karma. The karma levels are now stored on the forum itself, allowing customization. The various check of karma are done at model level and not at controller level anymore, leading to a more secure and easier to inherit behavior.
Merge pull request #771 from odoo-dev/master-forum-imp-tde

[IMP] forum: better management of karma-based actions, using calculated fields and view simplification