Update explanatory comment about the router
rough draft of sudoku puzzle solver

Does not yet do anything
Start elaborating the puzzle solver
More sodoku hacking
Copy in an actual puzzle
Add some puzzle documentation
Add a debugging print
Add the exhaustive un-ordered link search-test
partial work for unordered set permutations.
Forgot to add a default jobs value (1) for eval-candidate
no functional change; re-order two blocks of code

Otherise, its exactly the same code.
Add qtest target, to run only pattern-match tests

Shorten the build and test cycle.
more code movement
Minor ongoing restructuring
More baby steps to handle unordered sets correctly
Continuing work on unordered sets
minor bug fix, and extend the unordered test
Expand the uniordered test some more
try to get the recursive unorder link to work
Bug fix the recursive unordered link