Undo trivial change to 041.
PE 42 problem statement.
Utilities and tests for PE 42.
PE 43 problem statement.
Brute-force PE 43.

Moved digits->number into a "utils" library.
PE 42 solution, using code from PE 22.
Moved words-from-file into utils.rkt.
Problem statement for Listener crossword 4256.
Simple code for Listener problem.
Add full list of clues to Listener puzzle
Output the answers in base 24.
Add comments; simplify with-digits.