Merge pull request #220 from pfalabella/fix-build

fix build
added pernicious numbers and population count
ported comma quibbling
readme
Merge pull request #223 from pfalabella/quibble

Ported Comma quibbling
typo
Added RPN version of 24 game
Fixed build error with unused import
Merge pull request #222 from pfalabella/population-count

added pernicious numbers and population count
Incorporated PR comments
From Bool => Result
Updated with PR comments
Fixed token
Merge pull request #224 from prakhar1989/24-game

Added RPN version of 24 game
add url to knapsack 0-1
Merge pull request #225 from jschaf/add-url

add url to knapsack 0-1
Fixed check_file
Fix create_file
Fix filesize
Remove trailing whitespace