Test release with some small changes

This is mostly a test release that includes a few small changes.

• the black .exe icon and the "unknown" icon (shown when no controller was detected) were replaced with higher resolution versions. The "unknown" icon is also a multi-resolution ICO file (includes 16, 32 and 48px icons) to test if this works on high-res screens (for example 4k). See discussion in issue #6 .
• a new check was added that should automatically remove a triggered toast when battery level returns to a good state. This was brought to my attention on reddit. Note that it currently should only work when battery level switches to low/medium/high, not when the controller switches to any other state.