add ipc code
implement initial work on IPC-based execution

linux-only right now
change executable name to serialoscd
hack for changing process name on linux
implement IPC in iokitlib detector
move disable_subproc_waiting() into serialosc.c
fix missing ipc.h include in detector/iokitlib.c
remove unused variable in iokitlib.c
process IPC messages from device subprocesses
remove dnssd (bonjour) code
change the target to serialoscd in a few more places
fix memory leaks in sosc_config_create_directory()
fix memory leak in src/config.c
refactor IPC code, add SOSC_DEVICE_INFO
initial datastore impl.
implement SOSC_DEVICE_READY in server.c
messy implementation of /serialosc/list OSC discovery
implement device notifications
move manager code into manager/posix.c
rename "manager" to "supervisor"