unarist authored Nov 09, 2017 and Eugen Rochko committed Nov 09, 2017

* Show confirmation dialog on leaving WebUI while composing

Currently, Back button and Back hotkey can cause leaving from WebUI, as well as browser's back button. Users may hit those buttons accidentally, and their composing text will be lost.

So this prevents it by showing confirmation dialog from `onbeforeunload` event.

* Fix message and comments