[ENH] Articles: Add general watch event article_* (global)
[ENH] Watch articles : add an eye somewhere (Closes: 1755)
[ENH] add group watch to articles (Closes: 3100)
make watch types, titles and URLs generally optional
[ENH] Admin Notifications: improve watch addition
[FIX] Admin Notifications: don't ignore email if user is filled
notificationlib: add get_global_watch_types()
[FIX] Wiki comments notification mails for an event all have the same watchId
optimize Wiki comments notifications
Thanks to Xavier de Pedro