deterministic puzzle generation, auto-resizing, better clue grouping
lots of internal refactoring around events, some leaks fixed.
clue grouping has been greatly improved; some groups would fail to be discovered to due to ordering.
option to disable tooltips
puzzle generation is now deterministic; use environment variable SEED to cause gwatson to re-do a specific puzzle. Needs UI for this.
Puzzle generation is still slow for large puzzles.