Remove toxic from core repository

New location is:
https://github.com/Tox/toxic
Merge pull request #516 from jin-eld/remove-toxic

Remove toxic from core repository (moved to https://github.com/Tox/toxic)
Removed nTox_win32
Added TOX prefix to enum.
Merge pull request #517 from stqism/screw-nTox_win32

Removed nTox_win32
Removed useless and broken tests.
Merge branch 'master' into new-api
New API done and tested.

Some stuff needs to be cleaned a bit though.