calc 2.15.0.4 release

The following are the changes in this release:

Fixed bug that caused calc to fail to compile filepos2z() in file.c
on little endian machines for the Debian apcalc package.  Thanks to
Martin Buck (m at rtin-buck dor de) for for fix.

Removed unused macros from zmath.h:

SWAP_B32_IN_HASH(dest, src)
SWAP_B16_IN_HASH(dest, src)
SWAP_B8_IN_HASH(dest, src)
SWAP_B32_IN_FLAG(dest, src)
SWAP_B16_IN_FLAG(dest, src)
SWAP_B8_IN_FLAG(dest, src)

When SWAP_HALF_IN_B32(dest, src), SWAP_B32_IN_FULL(dest, src),
SWAP_B16_IN_HALF(dest, src), SWAP_B32_IN_bool(dest, src),
or SWAP_B32_IN_LEN(dest, src), SWAP_HALF_IN_FILEPOS(dest, src)
is an assignment such as:

(*(dest) = *(src))

We now case the dest and src pointers to the proper type before
referencing and performing the assignment.

Documented unexpected behavior when calc is running in
"shell script mode" and the prompt builtin function is used
without the -p flag.  Updated help/prompt, help/unexpected
and the calc man page accordingly.

Unless calc is given the -p command line option, calc will reopen
stdin as /dev/null instead of just closing stdin.  This prevents
subsequent opens grabbing the 1st file descriptor.

Disable regress tests 4709, 4710, and 7763 because they print
multi-byte sequences, which are just fine for calc, the awk
used to evaluate the regression suite output in some legacy
systems report a "multibyte conversion failure".

Added a number of missing Makefile variables to the "make env" rule.

The man command is used to format the calc.1 man page into calc.usage.

The "help calc" command now prints the formatted calc man page (calc.usage).
The "help man" command now prints the formatted calc man page (calc.usage).
The "help usage" command now prints the formatted calc man page (calc.usage).

The file, calc.cat1, is formed by gzipping the calc.usage
formatted man page.  The calc.cat1 is installed as the calc
cat section 1 man page.

Updated the Copyright string in version.c to refer to
the COPYING file and the "help copying" command.

Added calc.cat1 to .gitignore.  Using "sort -d -u" to sort .gitignore content.

Avoiding use of modern [[ and ]] in Makefile for those legacy systems
whose shell do not support them.  Be sure to use ||'s between []'s
to avoid problems with legacy shell such as the Bourne shell. *sigh*

Fixed the order of "help full" to match the order of topics listed
buy the "help help" command.

Sorted the halias[] help topics table in help.c using sort -d -u.