Function:	USERANGLE

Purpose:      User input interface routine for angular reals

Category:	user io

Author:	Do Kester

Use: integer USERANGLE(
	value,		O	doubleprecision
	nmax,		I	integer
	default,	I	integer
	key,		I	character*(*)
	mess )		I	character*(*)

	userangle	number of items entered

	value		result
	nmax		maximum number of values
	default		default level
	key		prompt string
	mess		accompanying message

Description:
     The string(s) presented to KEY may be written in two formats
     1. It can consist of one string containing 3 (or less) numbers
     separated by a delimiter from the set 'dDhHmMsSrR'. They mean
     the obvious: the degrees (or hours) are separated by a 'd' ('h') 
     from the minutes which in turn are separated by an 'm' from 
     the seconds. The seconds may be closed by an 's'. Minutes and
     seconds may alternatively be indicated by a single quote (') and
     a double quote (") -not 2 single quotes-. An 'r' indicates radians.
     2. The second format consists of 3 or less strings, each a valid
     fortran real, closed with a unit indicator: Hour, Degree or Radian.
     The unit indicator is obligatory for an interpretation as 
     degrees(hours) minutes and seconds. When none is given each string 
     is interpreted as an individual value (in degrees). The strings are
     separated from each other by one or more blanks (more blanks are
     equivalent to one) or by one of the set ',;:' (more of these
     separate empty strings which result in a zero on that position.)
     All numbers must comply to the fortran reals. If the
     number is to be negative, the first character should be a '-'.
     Some examples:
	format 1  	 format 2	result

       120d30m15s      120 30 15 deg	120 + 30/60. + 15/3600.
       -60d12.5m       -60:12.5 d	-( 60 + 12.5/60. )
       12h30            12;30 hours	( 12 + 30/60.            ) * 15
       12h30s           12;;30 h	( 12 +        + 30/3600. ) * 15
       12.3             12.3		12.3
	4r		  4 Radian	4 * 180 / pi

Externals:  	USERTEXT NELC
References:	former name in Geisha: gucala
Update:       890109  Timo Prusti, unification of versions
               880322  Do Kester
		28 Nov 1990 Do Kester, gipsy code
               19 Nov 1991 Pjotr Roelfsema, changed use of EXACT default
		07 Jan 1992 DK, better conformance to default levels
		03 Sep 1992 DK, initialization of input string to blanks
				and ios initialized to 0