Merge remote-tracking branch 'cpradio/keyboard-binding-incoming-updated-topics'

Conflicts:
	config/locales/client.en.yml
Merge branch 'master' of http://github.com/discourse/discourse
Merge branch 'master' of http://github.com/discourse/discourse
FIX: Firefox j/k post navigation is inconsistent
https://meta.discourse.org/t/j-k-navigation-in-lengthy-topics/18945
Merge pull request #2729 from cpradio/firefox-kbd-post-navigation

FIX: j/k navigation for posts using Firefox