Removed SolutionTreeNode Applicative and tightened up Answer Show
Bumped up project artifact versions
More refactoring to clarify intent
Added the AllArrays Answer extractor
Made Problem a model of Semigroup

Since a Problem requires at least one Equation, it cannot define a
sensical Monoid.  However, it easily satisfies the conceptual
requirements for being a Semigroup.
Bumped up dependent versions and furthered the Sudoku example

Unfortunately, the Sudoku solver is taking an inordinate amount
of time to complete.  Therefore, the launcher script prints a message
and does not run the example.  Finding what is causing the performance
is top priority.
Migrated load-vessels.sh to use the start script