gdl2.icn: Procedures to get directory lists

link gdl2
August 14, 1995; Richard L. Goerwitz and Charles Shartsis
Requires: UNIX or MS-DOS
This file is in the public domain.

 Gdl returns a list containing everything in a directory (whose name
 must be passed as an argument to gdl).  Nothing fancy.  I use this file
 as a template, modifying the procedures according to the needs of the
 program in which they are used.

NOTE: MSDOS results are all in lower case

Modifications:
1) Fixed MSDOS routines.
2) Added gdlrec which does same thing as gdl except it recursively descends
  through subdirectories.  May choose which Unix utility to use by passing
  in method parameter.  See below.