Add a confirmation of the cancel action

[nqst]

If the user accidentally presses Cancel button [x], all of their selected files are gone forever. It might be hurtful sometimes.

I propose to ask users whether they really want to cancel the upload and start from scratch, without those files.

[kvz]

That X is dangerously close to the pause button, especially when i'm using a touch interface, I might hit the wrong button accidentally and lose all my work/progress, which could amount to something if i had picked files from a bunch of remote providers.

Should likely be part of the statusbar so you also get this behavior without the dashboard, etc.

[kvz]

We've moved this to our backlog, closing this issue here now but we'll re-open when we get to it

[MentalGear]

how is this completed? @kvz