Milestone libobby 0.2.0

Version 0.2.0:

• This version is *not* protocol compatible to 0.1.0!
• New features (in no particular order):
  • Better win32 network handling
  • Many internal improvements
  • Adjusted to the new features available in net6 (depends on 1.1.0)
  • Document synchronisation on request
  • Global session passwords
  • Basic user authentication to protect the nickname
  • Localisation through GNU gettext
• Changes in the build system:
  • New dependency on GNU MP: The GNU multi precision arithmetic library provides big integers which are used to secure the password transmission on the wire.
  • New optional dependency on `howl': The howl library is used to provide local network service publishing and discover through Zeroconf.