calc: C-style arbitrary precision system Files

The following are the changes in this release:

    Fixed many typos in comments of the Makefile thanks to the review
    work of Michael Somos.

    Fixed typo in "help sysinfo".

    The Makefile rule, debug, is now more verbose and prints more information
    about the calc compiled constants.

    Added a more of calc resource files by
    Christoph Zurnieden <czurnieden at gmx dot de> including:

    infinities.cal - handle infinities symbolically, a little helper file
    intnum.cal - implementation of tanh sinh and Gauss-Legendre quadrature
    smallfactors.cal - find the factors of a number < 2^32
    strings.cal - implementation of isascii() and isblank()

    Reformatted some calc resource files.  Cleanup in comment the headers
    of some calc resource files.

    Minor formatting changes to a few help files.

    No need to be special picky about the test8900.cal calc resource file.

    Added a number of ctype-like builtins:

    isalnum - whether character is alpha-numeric
    isalpha - whether character is alphabetic
    iscntrl - whether character is a control character
    isdigit - whether character is a digit character
    isgraph - whether character is a graphical character
    islower - whether character is lower case
    isprint - whether character is a printable
    ispunct - whether character is a punctuation
    isspace - whether character is a space character
    isupper - whether character is upper case
    isxdigit - whether character a hexadecimal digit
    strcasecmp - compare two strings, case independent
    strncasecmp - compare two strings up to n characters, case independent
    strtolower - transform an ASCII string to lower case
    strtoupper - transform an ASCII string to upper case

    For details on these new builtins, see their help messages.
    Thanks goes to Inge Zurnieden <inge dot zurnieden at gmx dot de> for
    these new builtins.

    Calc source code is now picky v2.3 clean using:

	picky -s -v file file2 ..

    With the exception of:

	help/errorcodes.sed
	cal/set8700.line

    Due to the long lines in those files, we use:

	picky -w -s -v help/errorcodes.sed cal/set8700.line

    For more information about the picky tool, see:

	http://cis.csuohio.edu/~somos/picky.html

    Removed functions from strings.cal that have been replaced by
    the new ctype-like builtin functions.

    Fixed cal/Makefile to include missing intnum.cal file.

    Added detail_help_list make target to cal/Makefile.

    The detaillist make target in help/Makefile is now
    called detail_help_list.