gatttool: Use bluetoothctl strategy to handle standard input
gatttool: Use bluetoothctl strategy to handle standard input

Use GSource id returned by g_io_add_watch() instead of raw GIOChannel to
handle stdin and glib main loop.

mapfau/bluez,silent-snowman/bluez,pkarasev3/bluez,pkarasev3/bluez,mapfau/bluez,pkarasev3/bluez,ComputeCycles/bluez,mapfau/bluez,mapfau/bluez,silent-snowman/bluez,silent-snowman/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,pkarasev3/bluez,ComputeCycles/bluez,ComputeCycles/bluez