Supvisors

* Recreate the internal proxy to the local Supervisor if older than 20 minutes, in order to palliate the closure
of all channels inactive during 30 minutes in the Supervisor HTTP server.
This fixes a rare bug that has been introduced in **Supvisors** 0.17, and whose occurrence has greatly
increased after the refactoring of the **Supvisors** 0.18 internal communications.

* Swap Memory and Network statistics cards in the **Supvisors** Web UI.

* Handle the `PermissionError` exception when trying to get disk usage.

* Update CSS for overflow parts in the **Supvisors** Web UI.

* Fix the different perception of **Supvisors** instances about a process whose state is forced.

* Fix regression using the `SINGLE_NODE` distribution rule.

* Share the configuration of `stdout` and `stderr` log files between all **Supvisors** instances.
`has_stdout` and `has_stderr` are added to the result of the XML-RPC `get_local_process_info`.

* When the `software_name` option is set, it is used as a prefix in all log traces.

* Add disk usage and read/write statistics to the **Supvisors** Web UI.
Disk statistics are published to the event interface and the JAVA client has been updated accordingly.

* In the Application page of the **Supvisors** Web UI, add the possibility to expand the process information
from all **Supvisors** instances where it is configured.
In the event of a process conflict, a `Conciliate` button is displayed instead od a list of **Supvisors** instances.
Clicking on this button displays the Conciliation page.

* Split the Main and Conciliation pages of the **Supvisors** Web UI.

* The conflicting processes are highlighted in the Main page of the **Supvisors** Web UI.

* Change the access of the Conciliation page of the **Supvisors** Web UI, by clicking on the `CONCILIATION` state.
A click on the **Supvisors** logo always brings back the Main page.

* Fix the renaming of `DEPLOYMENT` state as `DISTRIBUTION` in the JAVA client.

* Refactoring of the **Supvisors** internal communications.
The `internal_port` of the **Supvisors** section in the Supervisor configuration file is no longer needed.
As a consequence, the `supvisors_list` option is simplified as follows: `<identifier>host_name:http_port`.
The transitional `SupvisorsInstanceStates.ISOLATING` state has been removed.
The remote **Supvisors** instance becomes `SILENT` as soon as the event publication fails due to a transport issue.

* Implement [Issue 50](https://github.com/julien6387/supvisors/issues/50).
A new tag `operational_status` in the Application rules allows to declare the formula applicable to evaluate the
application operational status.
`status_formula` is added to the result of the XML-RPC `get_application_rules`.

* Implement [Issue 15](https://github.com/julien6387/supvisors/issues/15).
A `StarterModel` has been added to **Supvisors** to give a prediction of the application distribution when started.
The command is available through the new XML-RPCs `test_start_application` and `test_start_process` and have been
added to `supervisorctl`.

* The **Supvisors** `core_identifiers` option and the **Supvisors** rules can now accept indifferently Supervisor
identifiers or keys with the `host:http_port` format.

* Update the `get_instance_info` XML-RPC so that the function accepts a stereotype as parameter.
As a consequence, it now returns a list of dictionaries.

* Add a `lazy` attribute to the `update_numprocs` XML-RPC, so that when set combined to a numprocs decrease,
**Supvisors** defers the obsolete processes deletion from the Supervisor configuration only when the processes stop
(exit, crash or later user request) instead of stopping them immediately.

* Add monotonic time in internal model and exchanges to cope with time updates while **Supvisors** is running.
Impact on the XML-RPC `get_instance_info`, `get_process_info` and on the event interface for instance status
and process event.

* Add new `get_statistics_status`, `enable_host_statistics`, `enable_process_statistics`, `update_collecting_period`
XML-RPCs to support the possibility to get and update the collection of host and process statistics.
The corresponding commands `stats_status`, `enable_stats` and `stats_period` have been added to `supervisorctl`.
The JAVA client includes the new XML-RPCs.

* Add new `get_all_inner_process_info` and `get_inner_process_info` XML-RPCs to support debug investigation.
They return internal information on the processes declared on a **Supvisors** instance.

* Move the host statistics collector to the statistics collector process.
The option `stats_collecting_period` is now applicable to host statistics collector.

* Re-apply the eventual process `extra_args` when restarting the application.

* In the Supervisors navigation menu of the Web UI, add a red light to Supervisor instances having raised a failure.

* Allow the display of a software name and icon at the top of the **Supvisors** Web UI.
The options `software_name` and `software_icon` have been added to the **Supvisors** section of the Supervisor
configuration file.

* All internal identifiers are now based on the `host:http_port` format.

* Rename the `DEPLOYMENT` state as `DISTRIBUTION` state to lift ambiguity ("deployment" is rather connoted when dealing
with the orchestration domain).

* Rework **Supvisors** `RPCInterface` exceptions.

* Rework the style of the **Supvisors** Web UI.

* Fix bug that was randomly blocking **Supvisors** on restart or shutdown, due to a stdout flush hanging in
multiprocessing bowels. The statistics Process is now started before any other thread.

* `guest` time removed from because CPU calculation because it is already accounted in `user` time on Linux.

* Fix process CPU so that it corresponds to the Linux `top` result.

* Use the latest versions of Sphinx-related modules for documentation, as `sphinx-5.0` is now the minimal dependency.

* Fix regression when displaying the Network statistics in the **Supvisors** Web UI.

* Add restrictions to `flask-restx` dependencies.