Sdss-clu

🚀 New

* Added a `FakeCommand` that writes to the log and that can be used when a command may not be present.

✨ Improved

* [104](https://github.com/sdss/clu/issues/104) The existing `cancellable` decorator did not work in subcommands. The decorator has been removed and now it's possible to pass `cancellable=True` to the command decorator (e.g., `command.parser.command(cancellable=True)`). This takes care of adding a `--stop` option to the command. The underlying behaviour of command cancellation has not changed.

🔧 Fixed

* Do not try to update model when a keyword from Tron cannot be parsed.

🔧 Fixed

* Do not use a task to update the model. This caused failures when messges where being sent from a function called with an executor.

🔧 Fixed

* Fixed a bug in which commanders with multiple dot-separated components would not be correctly interpreted by `handle_reply()` and the CLI.
* Command code `e` does not fail the command. This prevents cases of finishing/failing the command after it has already been failed.
* Improved the performance of the CLI by outputting all the parts of the message at once.

🚀 New

* Support Python 3.10.

✨ Improved

* [101](https://github.com/sdss/clu/issues/101) The legacy actor now accepts command strings with a commander id (e.g., `APO.Jose 10 status`). The commander id is stored in the `Command` object. Added a `Command.send_command()` that will call the remote command propagating the commander ID. For example, if a command has commander `APO.Jose` and sends a command to `guider`, the `guider` actor will receive a command with commander `APO.Jose.guider`.
* [102](https://github.com/sdss/clu/issues/102) When calling a model or property callback, ensure that the arguments sent are a frozen copy of the state of the model/property at the time of the callback. This prevents that if a model is updated twice in quick succession, the callback may receive only the second value. A consequence of this change is that the model callback now receives a flattened dictionary with all the model keywords as the first argument.
* If not specified, a message with code `e` or `f`, or an exception, will use the keyword `error`.

✨ Improved

* [99](https://github.com/sdss/clu/issues/99) Add `exception_module` value to the output of an exception.
* [sdss/sdsstools29](https://github.com/sdss/sdsstools/issues/29) Allow to pass a custom PyYAML loader in `from_config()` that will be forwarded to `read_yaml_file()`.
* Actors now accept `<actor> --help` with the same result as `<actor> help`.
* Add `additional_properties` parameter to `LegacyActor`.
* When a legacy actor starts, if there is a `TronConnection` available it will try to send a `hub startNubs <actor>` to initiate the connection.

🔧 Fixed

* Use `clu.client` for `TronConnection.send_command()`.
* If a command in a `LegacySurvey` actor is left running after the client closes the connection, it would still try to output messages to it, causing a `socket.send() raised exception` error. Now if the client exists the command continues running, but outputs to that client are ignored.