Updates for presentation

devel/example_devel/instructor/cs108/unitgrade_data/cache.db

docs/presentation2022/index.tex

examples/presentation/instructor/cpp_course/tests_ex6.py

...les/presentation/instructor/cpp_course/tests_ex6_grade.py

...instructor/cpp_course/unitgrade_data/Fractions_Basics.pkl

...uctor/cpp_course/unitgrade_data/Fractions_from_string.pkl

...resentation/instructor/cpp_course/unitgrade_data/cache.db

...course/unitgrade_data/main_config_tests_ex6.artifacts.pkl

...ples/presentation/instructor/cpp_exam/tests_exam_grade.py

...entation/instructor/cpp_exam/unitgrade_data/Q1Vectors.pkl

...presentation/instructor/cpp_exam/unitgrade_data/Q2RLE.pkl

...tation/instructor/cpp_exam/unitgrade_data/Q3Groceries.pkl

...ion/instructor/cpp_exam/unitgrade_data/Q4FilterBuffer.pkl

examples/presentation/instructor/deploy.py

examples/presentation/instructor/intro_python/exam.py

...les/presentation/instructor/intro_python/exam_complete.py

...esentation/instructor/intro_python/exam_complete_grade.py

examples/presentation/instructor/intro_python/exam_grade.py

...instructor/intro_python/unitgrade_data/Q1_WaterHeight.pkl

...tor/intro_python/unitgrade_data/Q2_AstronomicalSeason.pkl