Because of `placement.under_mouse` (and without
`placement.no_offscreen` fixing it), this will cause the tooltip to hide
immediately again.
There is no need for hooking into this signal, but this adds a click
handler to close the tooltip when clicking into it.
This splits the logic for `delay_show` out of `show`/`hide`, and handles
an already stopped timer. The timer gets also stopped after the tooltip
has been displayed.
Ref: https://github.com/awesomeWM/awesome/issues/371.
Daniel Hahler
Julian Wollrath