MCObot crashes when seeing utf8 in usernames

[Riot]

The log line: Disconnecting Rúben Monas causes:

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "./mcobot08.py", line 86, in run
    w['cb'](ln, mat.groups())
  File "./mcobot08.py", line 350, in on_mc_dc
    self.privmsg('#minecraftonline', '(MCS) %s was not allowed to connect: %s' % (nick, reason))
  File "/home/minecraft/ircbase.py", line 513, in privmsg
    self.send_line('PRIVMSG %s :%s' % (target, msg))
  File "/home/minecraft/ircbase.py", line 176, in send_line
    sent = self.server_sock.send((u'%s\r\n' % line).encode('utf-8'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 33: ordinal not in range(128)

[Riot]

UTF-8 encoding string with possible out of range usernames - resolves #93 (hopefully)

→ <<cset cbe3c1a7ef9c>>