Cmdtools-py

[see commit](https://github.com/HugeBrain16/cmdtools/commit/b704b33d89ace1e18094b70e8a75000423d97631)

see commit:
- [aff01e9](aff01e9cf59b19642e8340bac6a2e9913ddf8ca2)
- [9f98bb1](9f98bb1225caab9f73281fcb686fa7dd2c147fd2)

- assign attributes to class if callback is a method
- get command class only from specified command module
- use coroutine function for method `run` in class `CommandRunner` and `CommandRunnerContainer`

- add `command` extension
- add examples

[see commit](https://github.com/HugeBrain16/cmdtools/commit/ebe7fd2e06d123cf4c3adb50b44f8592a54227a8)