Scc fixed a race condition hapenning while forking and execing the command
and receiving a signal that could keep make waiting forever. Signals
are correctly masked now to avoid this problems.
This implementation is ported from the scc compiler with
the author permission to re license it with sbase license.
Using this make implementation to bootstrap sbase removes
the problems found by some buggy make implementations
(specially in the case of OpenBSD). It has a drawback
that the options passed for parallel build with -j are
ignored(improvement are expected).
Due to the multi file nature of make, embedding it in
sbas-box creates some problems, and for now, we keep
it out of sbase-box.
