add new aversin and acoversin builtin functions.

Added new aversin(x, [,eps]) for inverse versed sine and acoversin(x, [,eps])
for inverse coversed sine.

Improved trig function help files to reference use of complex arguments
that while supported were not documented.

Removed old Makefile testing rules for make dbx and make gdb.

Improved "make run" to execute calccalc using shared libraries
from the local directory, and with reading of the startup scripts
disabled.

Changed "make prep" to perform various tests that are used to
help verify that calc is ready for a release.

Added Makefile testing rule testfuncsort to check for the sort
of the builtin function list.  Changed the order that builtin
functions are listed by "show builtin" and the help/builtin to
match the sorting of "LANG=C LC_ALL=C sort -d -u".

help/acos

@@ -5,13 +5,13 @@ SYNOPSIS
     acos(x [,eps])
 
 TYPES
-    x		real, -1 <= x <= 1
+    x		number (real or complex)
     eps		0 < real < 1, defaults to epsilon()
 
     return	real
 
 DESCRIPTION
-    Returns the acos of x to a multiple of eps with error less in
+    Returns the inverse cosine of x to a multiple of eps with error less in
     absolute value than .75 * eps.
 
     v = acos(x) is the number in [0, pi] for which cos(v) = x.
@@ -20,14 +20,25 @@ EXAMPLE
     ; print acos(.5, 1e-5), acos(.5, 1e-10), acos(.5, 1e-15), acos(.5, 1e-20)
     1.0472 1.0471975512 1.047197551196598 1.04719755119659774615
 
+    ; print acos(5), acos(5i)
+    2.29243166956117768776i 1.57079632679489661923-2.31243834127275262025i
+
+    ; print acos(5+5i)
+    0.79039774680951249644-2.64919617780647114961i
+
 LIMITS
     0 < eps < 1
 
 LINK LIBRARY
     NUMBER *qacos(NUMBER *x, NUMBER *eps)
+    COMPLEX *c_acos(COMPLEX *c, NUMBER *epsilon)
 
 SEE ALSO
-    asin, atan, asec, acsc, acot, epsilon
+    sin, cos, tan, cot, sec, csc
+    asin, atan, acot, asec, acsc
+    versin, coversin
+    aversin. acoversin
+    epsilon
 
 ## Copyright (C) 1999,2023  Landon Curt Noll
 ##