0.6

• GTK3 support (use './autogen.sh --without-gtk3' to use GTK2 instead)
• Notifications support (use './autogen.sh --without-libnotify' to disable)
• New translations: Italian and Russian
• Tooltip is more informative
• Improvements in build architecture:
  • Travis support (used by GitHub)
  • Doxygen documentation added to the code (type 'make doc')
  • 'data' split in sub-directories, populated with Makefiles.am
  • use 'intltool' instead of 'glib-gettext' to handle translations
  • desktop file is now translated and part of POTFILES
• Better handling of USB soundcards that are unplugged:
  • A notification is sent
  • Another soundcard in the list (starting with the default) is opened,
    so that PNMixer is still usable and useful
  • If USB card is re-plugged afterward, one should click 'Reload Alsa'
    in the popup menu, so that PNMixer selects the USB card
• Lots of bug fixes