main: Use glib signal handler
main: Use glib signal handler

Writing anything to syslog in the signal hander is in danger
to deadlock with any ongoing syslog write (syslock is taking
a mutex). Fortunatly, BlueZ's signal handler doesn't do this,
therefore the change isn't strickly necessary, but the same changes
were done to oFono and ConnMan. So this patch streamlines BlueZ
with the other projects.

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