Sending mouse events to the terminal

[dantepippi]

Sending terminals the ANSI/VT commands for mouse events
Closes #579

[imsnif]

Hey, @dantepippi - is this PR ready? I just noticed it's been marked as ready for review a while ago. I don't think I get notifications for that sort of thing. :)

[TheLostLambda]

Seems good overall to me, but causes some issues when in something like nvim and there is also a scrollback on the terminal. It still tries to scroll the scroll-buffer instead of just passing through the event. Perhaps we need to listen out for applications wanting to capture the mouse? If there is a signal for that?

[tlinford]

@TheLostLambda There are actually multiple signals related to mouse events: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-Mouse-Tracking.
So for example the sequence we are using to enable mouse mode (via Termion) is: "?1000h\x1b[?1002h\x1b[?1015h\x1b[?1006h"

[imsnif]

Iirc this is not ready yet, so I guess that's why it's still not working :)

[tlinford]

Closing this as it was superseded by #1191.