Optional sound upon successful login

Like with Skype I think that it would be nice if there was a sound upon login. Just a fun little jingle of some sort. Though the feature would probably be on by default, it would probably be optional as some may not want it, but I think that it would be rather nice.

I already made the feature request here but I was told that I should also do so here.

[lehitoskin]

"Login" is kind of a weird thing with Tox. What is usually described as "logging in" is when you successfully create a Tox instance or when you successfully bootstrap into the network, but this doesn't particularly mean you're "in". You could also have it wait until you've connected to someone that's online (and then, without a doubt, you're in the network), but that means you might be waiting quite some time if your only Tox friend happens to be offline.

I think the best timing for the sound is when the client successfully bootstraps from the network. That's as good a time as any (outside of when you connect to an online friend) to say that you've logged in.

[Zer0-One]

I'll add this to the repository description soon.