lsysmap.icn: Program to map L-system symbols

This program maps the symbols in L-Systems.

The following options are supported:

     -i s    input symbols for mapping; default &ucase
     -o s    output symbols for mapping; default &ucase
     -a      put symbols for axiom production in alphabetical
               order (ignores -i and -o)

symbol strings are given on the command line, as in

     lsysmap -i ABCD -o DCBA <exam.lys

There is little error checking.  It's possible to produce an invalid
L-system by creating duplicate nonterminals or changing metacharacters.

The program handles two-level grammars using the first axiom symbol.