Work in progress group chats.

Not done yet.
Fixed small problem.
Possibly fixed LAN discovery on some configurations.
Function for retreiving a list of friend numbers

This should allow clients to sync the Tox friend list with their UI/etc.
lists.
Merge pull request #559 from jin-eld/friendlist

Function for retreiving a list of friend numbers
Base of group chats seems to be working now.
Merge branch 'group-chats'
Added name lengths to friend names.
Fixed autotest, increased MAX_STATUSMESSAGE_LENGTH.
Allow to build vs nacl instead of libsodium

By default libsodium is used. Only if --enable-nacl is specified, then
nacl will be used instead of libsodium.

Pass locations of nacl headers and libraries by using the following
options:

--with-nacl-headers=/home/me/somewhere/nacl-20110221/build/469/include/amd64/
--with-nacl-libs=/home/me/somewhere/nacl-20110221/build/469/lib/amd64/
Merge pull request #562 from jin-eld/nacl

Allow to build vs nacl instead of libsodium
Added TODO list and made m_copy*_statusmessage functions return length of copied buffer on success.
Merge branch 'master' of https://github.com/irungentoo/ProjectTox-Core
Update TODO
Merge pull request #563 from kigu/patch-1

Update TODO
Removed friendstatus from client API
Modified test
Merge pull request #564 from nurupo/friendstatus-patch

Removed friendstatus from client-side API, replacing it with alternative functions
Updated README.
Messaging now works in group chats.