sigset_t change (part 1 of 5) -----------------------------
sigset_t change (part 1 of 5)
-----------------------------

Rename sigaction, sigprocmask, sigpending and sigsuspend to
osigaction, osigprocmask, osigpending and osigsuspend (resp)
and add new syscalls for them to support the new sisgset_t
without breaking existing binaries.

Change the prototype of sigaltstack to use the typedef stack_t
instead of struct sigaltstack to reflect that it is SUSv2
compliant.

Also, rename sigreturn to osigreturn and add a new syscall
to support the modified stackframe. The change is caused by
sigreturn operating on ucontext_t now and the fact that
siginfo_t has been updated to conform to SUSv2.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase