Fix various errors in german translation
Merge pull request #1311 from adrianlang/fixGerman

Fix various errors in german translation
Don't include `user_deleted` posts in emails.
Add `Discourse.Singleton` class mixin for creating singletons.
Convert `Discourse.User` to use `Discourse.Singleton`
Convert `Discourse.Site` and `Discourse.ScreenTrack` to use `Discourse.Singleton`
Fix delete user button on admin/user page so it's enabled at the right times, and update its title attribute to be more helpful
Updated docs for `Discourse.Singleton`
Suggested Topics tweak: Prefer topics in the same category
FIX: Should allow support for ember list view
Use Ember.ListView for blocked emails list
Use Ember.ListView for staff action logs page
Add filter by action to staff logs page
Put staff user in the first column
FIX: Notification counters were being updated incorrectly.
Tiny CSS change: add background to inline code values.
Include a list of more new topics in the digest emails at the bottom
Add filtering to staff logs page
Fixes #1292. PR will come for the image in a minute.
add link to main website at top