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
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