GAL canvas pans forever if tool canceled while panning

[John Beard]

This is a rather annoying bug in the GAL canvases (both OpenGL and Cairo) on current master (98e3bfb95)

To trigger it:

* Activate the router tool
* Activate the auto-panning by clicking and starting a track
* Move the cursor off the canvas - the canvas will start to pan
* Press "Esc" to exit the tool
* The tool will be exited (and the cursor will disappear), but the canvas will continue to pan as before, even if you bring the pointer back onto the canvas.
* Clicking on the canvas will stop the panning, pressing "Esc" or "Home" does not stop it.

This doesn't seem to happen for the drawing tools (line, circle, arc, etc).

This is particularly annoying, because when the canvas pans unexpectedly because the tool is still active, the reflex is to hit "Esc" which makes it worse as moving the cursor back to the canvas will then not be enough to stop it working.

[John Beard (john-j-beard)]

Setting Medium because it's a pretty jarring bug that's quite frustrating as it happens when the user is already "confused" about the tool state.

[KiCad Janitor (kicad-janitor)]

Fixed in revision f599f10a032880ecf13e7bc2e6c017e422fd18c9
https://git.launchpad.net/kicad/patch/?id=f599f10a032880ecf13e7bc2e6c017e422fd18c9