Allow to move the image freely

[danlefebvre]

Hello ! It's easy to move the overlay image down using only the mouse, but it's locked when trying to move the image up again and we need to use the keyboard instead, which is pretty slow. Could you allow to move the image freely in both directions ? Another nice feature would be to move the image faster, let's say 20px, when pressing Shift+↑ or Shift+↓

[krin-san]

I guess the whole idea behind the Locked state is to allow mouse clicks to go through the application window. In order to move it freely using mouse: unlock, move then lock again.

I like the idea of introducing a separate key binding to move window quickly using keyboard.