Merge pull request #47 from stal888/master

Add custom user statuses to core, updated nTox to support nicknames and user statuses.
Status packet is now id 49 (It's cleaner that way).
Update TODO.txt
Added installation guide
Merge pull request #49 from nurupo/master

Added installation guide
Merge pull request #48 from sometwo/patch-1

Update TODO.txt
Move packet IDs to Messenger.h.