calc: C-style arbitrary precision system Files

The following are the changes in this release:

    Added notes to help/unexpected about:

	display() will limit the number of digits printed after decimal point

	%d will format after the decimal point for non-integer numeric values

	%x will format as fractions for non-integer numeric values

	fprintf(fd, "%d\n", huge_value) may need fflush(fd) to finish

    Fixed Makefile dependencies for the args.h rule.

    Fixed Makefile cases where echo with -n is used.  On some systems,
    /bin/sh does not use -n, so we must call /bin/echo -n instead
    via the ${ECHON} Makefile variable.

    Add missing standard tools to sub-Makefiles to make them
    easier to invoke directly.

    Sort lists of standard tool Makefile variables and remove duplicates.

    Declare the SHELL at the top of Makefiles.

    Fixed the depend rule in the custom Makefile.

    Improved the messages produced by the depend in the Makefiles.

    Changed the UNUSED define in have_unused.h to be a macro with
    a parameter.  Changed all use of UNUSED in *.c to be UNUSED(x).

    Removed need for HAVE_UNUSED in building the have_unused.h file.

     CCBAN is given to ${CC} in order to control if banned.h is in effect.

     The banned.h attempts to ban the use of certain dangerous functions
     that, if improperly used, could compromise the computational integrity
     if calculations.

     In the case of calc, we are motivated in part by the desire for calc
     to correctly calculate: even during extremely long calculations.

     If UNBAN is NOT defined, then calling certain functions
     will result in a call to a non-existent function (link error).

     While we do NOT encourage defining UNBAN, there may be
     a system / compiler environment where re-defining a
     function may lead to a fatal compiler complication.
     If that happens, consider compiling as:

	make clobber all chk CCBAN=-DUNBAN

     as see if this is a work-a-round.

     If YOU discover a need for the -DUNBAN work-a-round, PLEASE tell us!
     Please send us a bug report.  See the file:

	BUGS

     or the URL:

	http://www.isthe.com/chongo/tech/comp/calc/calc-bugrept.html

     for how to send us such a bug report.

     Added the building of have_ban_pragma.h, which will determine
     if "#pragma GCC poison func_name" is supported.  If it is not,
     or of HAVE_PRAGMA_GCC_POSION=-DHAVE_NO_PRAGMA_GCC_POSION, then
     banned.h will have no effect.

     Fixed building of the have_getpgid.h file.
     Fixed building of the have_getprid.h file.
     Fixed building of the have_getsid.h file.
     Fixed building of the have_gettime.h file.
     Fixed building of the have_strdup.h file.
     Fixed building of the have_ustat.h file.
     Fixed building of the have_rusage.h file.

     Added HAVE_NO_STRLCPY to control if we want to test if
     the system has a strlcpy() function.  This in turn produces
     the have_strlcpy.h file wherein the symbol HAVE_STRLCPY will
     be defined, or not depending if the system comes with a
     strlcpy() function.

     If the system does not have a strlcpy() function, we
     compile our own strlcpy() function.  See strl.c for details.

     Added HAVE_NO_STRLCAT to control if we want to test if
     the system has a strlcat() function.  This in turn produces
     the have_strlcat.h file wherein the symbol HAVE_STRLCAT will
     be defined, or not depending if the system comes with a
     strlcat() function.

     If the system does not have a strlcat() function, we
     compile our own strlcat() function.  See strl.c for details.

     Fixed places were <string.h>, using #ifdef HAVE_STRING_H
     for legacy systems that do not have that include file.

     Added ${H} Makefile symbol to control the announcement
     of forming and having formed hsrc related files.  By default
     H=@ (announce hsrc file formation) vs. H=@: to silence hsrc
     related file formation.

     Explicitly turn off quiet mode (set Makefile variable ${Q} to
     be empty) when building rpms.

     Improved and fixed the hsrc build process.

     Forming rpms is performed in verbose mode to assist debugging
     to the rpm build process.

     Compile custom code, if needed, after main code is compiled.