Merge pull request #2572 from awesomerobot/master

fixing wmd-editor button background
FIX: hidden helper class is important
Caps Lock clearly needs more exclamation sign
missed a spot for more /!\
FIX: cors setting was broken

Some days I wonder why we bother taking a whole gem
dependency when 10 lines of code does the job right
Merge pull request #2573 from fantasticfears/patch-5

FIX: hidden helper class is important
Revert "FIX: hidden helper class is important"
Merge pull request #2575 from discourse/revert-2573-patch-5

Revert "FIX: hidden helper class is important"
minor alignment fix