We cannot add attributes to a method, and I do not want to wrap the
callback function or to modify the callback function set, so I
moved the check to the runtime. It should not change the performance.

- Allow two types of callback functions: 1 and 2 arguments. Functions
The variable's name is given before the the value if the a function that
takes 2 arguments in given.

- the file `level.py` starts to be really huge.
So I splitted it into 4 parts.
- update formating on `utils.py` and `arcade_ui.py`

Add the variable name to value_change events so we can use
a single handler to handle a set of variables.

- add manual and auto test.
- add shell scripts that runs all the auto test
- an auto test directory must have a `run` recipe that runs
the test. The script will test the return code of the recipe.

improve:
- Add git hooks that run all the test?

- Add annotation
- Update submodule
- Add basic event list

WIP.
Assumed that all the encountered bp and wp are not user defined
yet. Still waiting for proper bpno and wpno in easytracker.

- Use defaultdict for list of variables
- Add handler for breackpoints and watchpoints
- Fix ugly code evaluation
- Add support for map

- Add basic documentation in docstrings.
- New features (watch, track, alias)
- Update conditions (now in plain python with aliases)
- Use defaultdict

TODO maybe?
- sphinx docs from docstrings.
- rewrite the comment parser with `pyparse`.

- Condition are now in plain python syntax.
ex: player_x == 5 or player_y == 7