ADfgetl( <nHandle> --> <cLine>

Returns a line from a file whose handle is <nHandle>.  The return value,
<cLine> is stripped of the CRLF characters.  Returns a "" if it is at
end of file.

Example:
--------
func main()
local h := fopen( "OVERVIEW.F" )

do while !ADfeof( h )
   ? ADfgetl( h )
enddo
return nil