Refactoring ideas

[nergal-perm]

It is just an "umbrella" issue to track all the refactoring and improvement ideas as puzzles

[0pdd]

@nergal-perm the puzzle #26 is still not solved.

[0pdd]

@nergal-perm the only puzzle #26 is solved here.

[0pdd]

@nergal-perm 2 puzzles #53, #54 are still not solved; solved: #26.

[0pdd]

@nergal-perm 3 puzzles #53, #54, #85 are still not solved; solved: #26.

[0pdd]

@nergal-perm 2 puzzles #53, #85 are still not solved; solved: #26, #54.

[0pdd]

@nergal-perm all 4 puzzles are solved here: #26, #53, #54, #85.

[0pdd]

@nergal-perm the puzzle #120 is still not solved; solved: #26, #53, #54, #85.

[0pdd]

@nergal-perm all 5 puzzles are solved here: #120, #26, #53, #54, #85.