Log exceptions in separate generator test thread
Refactor: made private some Log methods
Changed tile size to 24
As pacman, also allow reverse after eating a ghost
Refactor: refer to tests by name
Extract MODEL tests from Tests.cpp
Refactor: mv tests test
Refactor: added comments
Test: eat 2 dots
Test: eat energizer
Test: eat fruit
Allow pausing game in GUI
Added --pause-at-end
Test: eat fruit, then a ghost
Fix: tests no longer ran
Fix: test_eat_fruit_ghost

Ghost score was wrong because it did not take into account ghosts in the
pen
Refactor: made did_pacman_win/lose private
Refactor: removed unused forward declaration.
Refactor: generated tests only depend on external state

Depending on implementation details such as fruit_ticks_left creates too
much coupling.
Test: eat 1 ghost