Add buttons for next song on notification hover.

[tgpraveen]

IMHO this should be a useful, don't show buttons always but on hover on notification, it will be useful.

[citruspi]

@tgpraveen,

I think this is a duplicate of this issue, so I'm closing it.

If you disagree, or have anything else to add, feel free to re-open this issue.

— @citruspi

[sebj]

Notifications now have a skip button as of #56 being merged in! Thanks @tgpraveen :)

[tgpraveen]

@sebj Thanks for implementing this :)

[sebj]

@tgpraveen No worries! 😃