This is a simple minecraft authentication server. It can be used by a server
admin to build a sign-up process that requires a valid minecraft account, or
to tie accounts to existing website users.

To use, extend authserver.AuthServer, adding your own logic to handle_auth. You 
can return either a string to kick the user with, or a twisted.defer.Deferred 
which will fire with the kick message. See demo.py for an example.

Requirements:
 * python 2.7
 * pycrypto
 * twisted