Additional bugfixes

[jstucke]

• re-enabled logging to find errors / bugs
• extended logging of dns and smtp servers (log earlier to cover more connections)
• fixed multiple bugs in servers:
  • dhcp:
    • removed call to transport.loseConnection as this crashes the server after the first received message (because dhcp uses "connection-less" UDP)
  • dns: fixed error in tcp listener
  • http + https: fixed KeyError
  • irc: fixed decoding error
  • pjl:
    • fixed decoding error
    • fixed server name in log entry
  • redis: fixed encoding error
  • smnp:
    • fixed encoding error
    • removed call to transport.loseConnection as this crashes the server after the first received message
  • ntp:
    • fixed struct error in ntp server
    • logged status correctly
    • removed call to transport.loseConnection as this crashes the server after the first received message
  • ssh: handled SSHException
  • socks5:
    • handled struct error
    • handled connection error

[giga-a]

@jstucke thanks!