document prompt in shell script mode, fix man formatting, legacy awk

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.  *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.

.gitignore

@@ -1,17 +1,17 @@
 # generic excluded patterns
 #
-# We sort the list below via: sort -u -f
+# We sort the list below via: sort -d -u
 #
-*,v
-*.BAK
-*.dSYM/
-*.exe
-*.o.tmp
-*.[oa]
 *~
-.*.swp
+*.BAK
 .DS_Store
 core*
+*.dSYM/
+*.exe
+*.[oa]
+*.o.tmp
+.*.swp
+*,v
 
 # files and directories created during the building of calc and other Makefile actions
 #
@@ -19,50 +19,51 @@ core*
 #	not consider development source.  Some other file(s) and/or programs
 #	generate these files.
 #
-# We sort the list below via: sort -u -f
+# We sort the list below via: sort -d -u
 #
-.dynamic
-.hsrc
-.static
+Makefile.our
+NOTES
 align32
 align32.h
 align32_tmp
 arc4random_tmp
 args.h
 cal/.all
-cal/test082.cal
 calc
-calc-static
 calc.1
+calc.cat1
 calc.spec
+calc-static
 calc.usage
+cal/test082.cal
 charbit.h
 chatbit
 chk_c
 conf.h
 const_tmp
-cscript/.all
 cscript/4dsphere
+cscript/README
+cscript/.all
 cscript/fproduct
 cscript/mersenne
 cscript/piforever
 cscript/plus
 cscript/powerterm
-cscript/README
 cscript/simple
 cscript/square
 custom/.all
 custom/libcustcalc*
 debug.out
+.dynamic
 endian
 endian_calc.h
 environ_tmp
 errcode
 errsym.h
+fpos_tmp
 fposval
 fposval.h
 fposval_tmp
-fpos_tmp
 func.show
 func.sort
 getpgid_tmp
@@ -127,6 +128,8 @@ have_urandom.h
 have_ustat
 have_ustat.h
 have_varvs
+help/COPYING
+help/COPYING-LGPL
 help/.all
 help/binding
 help/bindings
@@ -137,8 +140,6 @@ help/change
 help/changes
 help/contrib
 help/copy
-help/COPYING
-help/COPYING-LGPL
 help/cscript
 help/custom_cal
 help/errorcode
@@ -156,15 +157,14 @@ help/releases
 help/resource
 help/type
 help/usage
+.hsrc
 libcalc.*
 libcustcalc.*
 ll_tmp
 longbits
 longbits.h
-Makefile.our
 memmv_tmp
 newstr_tmp
-NOTES
 offscl_tmp
 outfile
 posscl_tmp
@@ -174,6 +174,7 @@ sample_many-static
 sample_rand
 sample_rand-static
 statfs_tmp
+.static
 status.chk_c.h
 strdup_tmp
 tags