Merge pull request #720 from nurupo/master

Fixed some memory leaks
Astyled and removed some useless files.
Fixed possible memory leak.
Added entry to TODO and a public key cracker (vanity key finder) to other/fun.
Added paragraph explaining how strings work in Tox.
All strings should now be forced terminated when received.
Made onion paths expire.
Onion now eventualy deletes friends from the DHT search.

This should improve long term bandwidth usage by a bit.
updated/fixed TODO list.
Fixed small bug in DHT.
Added custom userpackets.

A way to send and handle lossy UDP packets coming from friends.

Will be used for A/V.
Fixed issue.
Added callback for A/V usage.
Fixed some possible issues.