Cleanup 45 thru 49.
- Rename primeFactors to primeFactorsP, introduce unbounded primeFactors.
- Make searches in 46 and 47 unbounded.
- Use modPow in 48.
- Use ordered list membership in 49.
Cleanup 50 thru 59.
- dos2unix cipher1.txt
- Use accumulation of sums for 50.
- Remove upper bound on 51, use digits rather than strings.
- Use nChooseK for 53 (slower).
- Use attoparsec for 54, greatly simplify hand comparison.
- Use digits rather than strings for 55 and 57.
- Use attoparsec for 59.