Video grabber QoL enhancement.

[Admini]

Don't know why i missed this in past, but another good QoL addition would a sound for an error of download = since there is no any alarm for user that download is halted, due to some problem, it's easy to miss that some video download is "error-stuck" for long time already. Hope Admini will see this to reply.

Summing-up QoLs:
- grabber download progress on taskbar (when possible: size/number of pieces available)
- sound when download finished
- sound if download stopped with error
- option to pre-select location for grabber to auto-save

OK, we will consider your suggestions.