Switchman 1.7.2

A fix for something 1.7.1 broke, and updates that now check themselves.

• Clicking the link in the middle of the dial works again. 1.7.1 moved the full application list from a slice of the dial to the centre, and then swallowed every click on it — the dial only recognised clicks that landed on a browser, so pressing the middle cancelled instead of opening the list. Nothing else could reach the applications the dial had no room for.
• The dial keeps closer to your pointer near the edge of the screen. It was reserving 60 points of clearance for a shadow it does not draw.
• Automatic update checks are on unless you switch them off. They shipped off, which meant a copy could sit on an old build indefinitely and never hear that a fix existed. The check asks our server for a static file once a day and carries no identifier; About → Check for new versions automatically turns it off, and it stays off.
• Moving the pointer around the dial no longer rebuilds the whole thing several dozen times a second.