Is there anything out there that will catalog a collection of Sudoku puzzles (.SDK, .SDM, .SS, etc.)? I would like to see something that will:
1. Calculate difficulty level (and preferrably add it as a Sudocue comment line)
2. Identify/eliminate duplicates, including mere rotations/substitutions
3. Convert .SDK (and .SS) files to .SDM as well as .SDM to .SDK