clib2 Code

- Moved the __UtilityBase/__IUtility variable declarations into
a separate file.

- Simplified the library/open close code in "stdlib_main.c".

- raise() no longer resets the signal handler before it invokes the one
currently configured. It merely blocks the delivery of the respective
signal to prevent recursion.

- raise() now drops into abort() if a signal handler is set to
SIG_DFL. The exception is in SIGINT delivery, which has the
effect of printing a different termination message but otherwise
program flow takes the same path as abort().

- Moved the signal block mask and the signal function table out of
signal_data.c and into signal_raise.c where they are actually used.
This makes it possible to override the default definition of the
__check_abort_enabled variable in your own programs.

- The name of the public record locking semaphore has to be preallocated
for OS4 if the AllocSysObject() function is used to create it.

- Updated the specs file not to reference the main.o files any more.

- Clarified the caveats of the libm.a use.

- Ready for release...

- Oops, nearly broke fcntl() again for sockets.

- Small fixes to fcntl() and select() to cover the thread-safe
fd->fd_DefaultFile == ZERO case.

- Added a description of the thread-safe stdin/stdout/stderr behaviour.

- Activated the dormant thread-safe standard input/output/error
handling code.