remote process. This new implementation also passes all the test programs
I've written so far.
- When exceptions come from traps, no UNIX signal should evet be sent.
- Add a lock to ensure a debugger handles only one exception at a time
- Use a structure to hold flavor and behavior in exception ports, instead
of stuffing the two argument into an int.
- Implement new Mach services: thread_suspend, thread_resume and thread_abort
- Implement Darwin's ptrace PT_ATTACHEXC and PT_THUPDATE commands
- Handle NULL second argument correctly in sigprocmask.
- One mistake in the last commit (darwin_tracesig prototype)
