Refactor TopicView - extract filter method to FilterBestPosts

Still much to do but this should reduce the complexity scores
for TopicView
Add primary key `id` to `category_featured_topics` and `topic_users`
Refactor array concatenation
Simplify avatar lookup class
Update client.nb_NO.yml

Moar translations. Also jumped back and fixed what I could find of the ones with missing double quotes.
FIX: create an upload when FastImage throws an exception

FastImage might throw an exception when it isn't able to recognize a
file as being an image (ie. happens when users changes the extension
manually)

Also improved upload specs a lot
Fixed typo at nginx.sample.conf
display the size of the attachment in the preview

instead of adding it during post processing
v1 Complete translation for client.nb_NO.yml

All strings now have a first-take translation. Might have missed some due to the inconsistent use of double quotes, single quotes and no quotes (we're still good!).

I'm not entirely sure what happens when I apply edits to a still pending-for-pull patch; sorry if I goofed.
Locales: updated German locale, admin content like the admin section and flagging
Locale german: got another one
change the icon in the composer toolbar with a more generic upload icon

also changed all references to "images uploads" to a "uploads"
ooops, fixed CookedPostProcessor specs
simplify copy around merge and split
improve copy on daily action limit
widen @name autocomplete dialog 20%
Merge pull request #1193 from jbruni/master

Tiny typo fix (comment at nginx.sample.conf)
Merge pull request #1192 from cfstras/locale

Locales: updated German locale, mainly the admin section
Merge pull request #1188 from stephankaag/simplify_avatar_lookup

Simplify avatar lookup class
Merge pull request #1186 from stephankaag/add_primary_keys

Add primary key `id` to `category_featured_topics` and `topic_users`