Macro:	abbrev - check if a string is an abbreviation for another string

Synopsis:
	status abbrev(string complete, string abbreviation, int minlen)

Description:
	Find out if a string is the abbreviation of another.
	Returns true when 'abbreviation' is indeed an abbreviation of
	string 'complete' and has at least length 'minlen' chars.
	This call is compatible to REXX abbrev(), it is implemented
	as macro using extract().

Return value:
	returns 1 if abbreviation is an abbreviation of complete
	returns 0 if not

Examples:
	abbrev("look", "loo", 1)
		-> return true

	abbrev("smilingly", "sigh", 1)
		-> returns false

Note:
	Should be done via str[0..minlen] ;-) See 'man extract'!

	This is not a simulated efun but a MACRO defined in /include/auto.h .

See also: efun/extract