Pythonwhat

- Improve checking exceptions
- Improve checking file content

- Speed improvements

- Expose `_debug` function
- Update protowhat

- `state` is now the first argument to SCT functions (instead of a keyword argument)
- functionality is shared with protowhat:
- `Reporter`, `Chain`, `F` and logic SCTs are reused
- `State` and `Feedback` inherit
- `Dispatcher` handles parsing (decoupled from `State`)
- `Test` moved

Fixed

- Local setup with `setup_state` now works correctly (e.g. when the PEC contains a list comprehension)

- Add optional `force_diagnose` parameter to `test_exercise` to force passing the `diagnose` tests in `check_correct`.