Added two new flags to identify tests that are intentionally ignored
(usually because we don't want to implement the tested functionality
on current platform) and test serving as TODO list (usually indicating
that the tested functionality should be implemented on current plaform
in the near future.)
Replace `void f()` with `void f(void)`; the former means "a function
that takes any number of arguments, including none" while the latter
is what is actually intended: a function taking no arguments.
The first form also isn't strictly conforming ANSI/ISO C.
Based on UNIX sockets to avoid the vagaries of FIFOs
in asynchronous mode. Currently unlinks stale sockets
before binding and cleans them up again after shutdown.
