siginfo is disabled by default so building on new CPU
architectures does not require adjusting of siginfo.c anymore.
When needed, --siginfo can be used as option to ./waf configure
to enable the functionality
Backup repo: https://github.com/LADI/jack_control
dbus/jack_control is now submodule
jack_control is now always installed as part of jackdbus.
With dedicated repos for jackdbus and jack_control,
there is no point in having jack_control installation conditional.
Nedko Arnaudov