Sukaku Explainer v1.3.0.0

Major improvements to command line point efficiency:
Fixes #26, #27, #25.
The changes don't affect the rating, are backward compatible to serate, and seem stable.
Speed improvement compared to old serate is ~ x2 for some hard puzzles, insignificant else.
Update: It is worth to mention that this merge incorporates ALL other active branches.

Improvements on --format option

GUI accepts parsing most sudoku and sukaku formats including 729-character single line sukakus
and Pencilmark grids.

GUI puzzle generations has more categories to choose from