This makes the edit history overlay dark mode compatible by changing
the background to the dark blue along with changing the highlight
colors to work with white text and dark backgrounds.
This refactors and fixes unicode issues where entities don't display
properly due to being a special character that seems to be rendered
incorrectly in a non-deterministic way every time.
This either removes aria-hidden=true assignments from buttons with
text, or adds a span to only hide the 'x' symbol rather than the
button for closing buttons.
Fixes#268.
Modified significantly by tabbott to:
* improve code cleanliness / repetition
* add missing translation tags
* move code into message_edit.js
* correspond with the new backend.
* not display the option for messages only topic-edited
Brock Whittaker
Vaida Plankyte
aakash-cr7
Cynthia Lin
adnrs96
Kartik Maji