Pioreactor

- too much to list

- New plugin architecture
- New database tables: `od_reading_statistics`, `stirring_rates`
- New `pio` commands: `install-plugin`, `uninstall-plugins`
- improvements to `continous_cycle` dosing automation.
- hardware based PWM available on pins 1 & 3.

- IR LED now turns off between OD readings. This allows other LEDs to trigger and take readings.
- Removed leader jobs `time_series_aggregating` and `log_aggregating`
- `logs` table in database has more metadata
- New Kalman filter algorithm that includes an acceleration term
- New database table, `kalman_filter_outputs`, stores the output of the internal Kalman Filter.
- workers report back to leader additional system information including available memory and CPU usage.
- Added new temperature control and temperature automations for this app and to the UI.
- Added undervoltage alerts to logging
- Added initial version of a plugin system
- `pio run-always` for jobs not tied to an experiment (monitor, watchdog, etc.)
- faster database backup sync between Pioreactors
- Ability to measure your blank vials is available using the `pio run od_blank`, and in the UI under "Calibrate"
- Smarter algorithm for displaying time series in the UI
- Log table only shows the past 24 hours of events.

- new dosing automation: `continous_cycle`. Designed for using the Pioreactor as an inline sensor.
- stirring can now be dynamically adjusted between OD readings, for improved mixing (and hence more oxygen transfer). See settings in UI.
- custom timezone support is added in config.ini
- `download_experiment_data` is now called `export_experiment_data` - this has been updated on the UI as well.
- unpausing stirring will return the rate to the previous value, not necessarily the default value.

- fix GPIO mappings
- fix keyboard interrupts in pump actions
- fix race conditions in MQTT disconnects
- fixed a bug where a job's state would change to `lost` when another job (of the same type) would try to start.
- in `ADCReader`, changed from windowed moving average to exp. moving average to be more sensitive to recent changes in signal.
- Growth rate calculating is a bit more robust to i) users pausing the job to inspect the vial, and ii) to changing the stirring speed.
- mDNS alias is now configurable via the config.ini, so users could have multiple clusters without domain aliases colliding in the DNS.
- fixed GPIO mappings for PWM Amplifiers
- `inventory` in config.ini is now called `cluster.inventory`
- `ui.overview.rename` in config.ini is now called `ui.rename`

- fixed reconnect issues when leader went offline and then online
- pausing `dosing_control` now pauses sub jobs `dosing_automation`
- renamed `_algorithm` to `_automation` everywhere.
- ADC measurements are now run at exact time intervals (previously there was some drift). The `adc` job now publishes metadata about it's recording times.
- Improved error handling in `od_reading`