Added more builtin inverse conversion functions

Added builtin functions to convert between degrees, minutes and
    seconds and degrees under the config("mod") round rules:

	dms2d(d, m, s [,rnd]) - convert deg, min, and secs to deg
	dm2d(d, m [,rnd]) - convert deg, min to deg

	See help/dms2d and help/dm2d.

    Example:

	; print dms2d(12, 20, 44.16);
	12.3456

	; print dm2d(3601, -25.5594);
	0.57401

    Added builtin functions to convert between gradians, minutes and
    seconds and gradians under the config("mod") round rules:

	gms2g(g, m, s [,rnd]) - convert grad, min, and secs to grad
	gm2g(g, m [,rnd]) - convert grad and min to grad

	See help/g2gms and help/g2gm.

    Example:

	; print gms2g(12, 20, 44.16);
	12.3456

	; print gm2g(4001, -25.5594);
	0.57401

    Added builtin functions to convert between hours, minutes and
    seconds and hours under the config("mod") round rules:

	hms2h(h, m, s [,rnd]) - convert hours, min, and secs to hours
	hm2h(h, m [,rnd]) - convert hours, min to hours

	See help/hms2h and help/hm2h.

    Example:

	; print hms2h(12, 20, 44.16);
	12.3456

	; print hm2h(241, -25.5594);
	0.57401

help/d2dms

@@ -76,7 +76,7 @@ EXAMPLE
     ; global d, m, s;
 
     ; print d2dms(12.3456,d,m,s), d, m, s;
-    12.3456, 12, 20, 44.16
+    12.3456 12 20 44.16
     ; print d2dms(1234.5678,d,m,s), d, m, s;
     154.5678 154 34 4.08
     ; print d2dms(-1234.5678,d,m,s), d, m, s;