Incorporated onion into Tox.

Fixed a couple of issues related to that.
Onion servers are now DHT ready.
Small performance increases.
Fixed segfault.
Some optimizations and fixes.
Improved DHT bootstrap daemon

Supports "unlimited" number of bootstrap nodes in the config file, instead of
just 32.
PID and keys file paths are not limited by 512 chars anymore.
Doesn't read the whole list of bootstrap servers into a global datastructure
that just sits there after being processed once -- reads bootstrap servers
one by one, processing them between reads.
Supports IPv6.
Has an option for IPv6.
Supports LAN discovery.
Has an option for LAN discovery.
Writes to syslog.
Uses new functions introduced in the core.
`status` in the bash script now works.
Has a simple README, with instructions for Debian-based distros.
Tell github that README is a markdown file
Fixed some formatting
Renamed to fix build process
Fixed comments and variables' names
Fixed build
Added no_replay and added some things to the docs.
Astyled the code
Small protocol change for more replay attack prevention.

see the changes to Prevent_Tracking.txt
Commented out now useless code.
Some small improvements added.
Spellchecked everything
Fixed onion_test.
Merge pull request #688 from nurupo/dht_bootstrap_daemon

Improved DHT bootstrap daemon
Fixed spelling