UX: show category when moving post to exisiting topic
FIX: Opera Improvements (v12)

Fix issues with Opera 12 and its ability to utilize Discourse Composer window
https://meta.discourse.org/t/support-for-opera/20218
removed typo in invitation email template
FIX: BBCode blocks parser no longer mangles JsonML arrays
Merge pull request #2812 from kamilbielawski/invitation_email_typo_fix

FIX: removed typo in invitation email template
Merge pull request #2810 from cpradio/opera-composer-keyboard-shortucts

FIX: Opera Composer Keyboard Shortcuts
Merge pull request #2807 from techAPJ/patch-2

UX: show category when moving post to exisiting topic
Merge pull request #2811 from Elberet/fix-bbcode-blocks

FIX: BBCode blocks parser no longer mangles JsonML arrays
FIX: while header drop down is dropped, header is in front
FIX: 404 if we try to navigate to a non-existant page
lower band check as well
FEATURE: Enable topic entrance on mobile
use && instead of and
FIX: `undefined` label on Top dropdown on mobile
FEATURE: staff option to unhide a post
fix broken build