Added DBUS commands for getting/setting radio station

# Get Station List
dbus-send --print-reply --dest=net.kevinmehall.Pithos /net/kevinmehall/Pithos net.kevinmehall.Pithos.GetStationList

# Get Active Station
dbus-send --print-reply --dest=net.kevinmehall.Pithos /net/kevinmehall/Pithos net.kevinmehall.Pithos.GetCurrentStation

# Set Active Station
dbus-send --print-reply --dest=net.kevinmehall.Pithos /net/kevinmehall/Pithos net.kevinmehall.Pithos.SetCurrentStation string:"QuickMix"