Glasgow Embedded / Glasgow - History

device.hardware: nudge the operator to reflash obsolete devices.

Fixes #239.
Closes #247.

device.hardware: check if device is busy before loading firmware.

On Linux multiple userspace applications can send control requests
to a device without being aware of each other. Claim every interface
to ensure mutual exclusion with any other application.

On other OSes device access is already exclusive.

Fixes #241.

target.hardware: whitelist `PROCESSOR_ARCHITECTURE`.

It is used by wasmtime-py to determine which DLL to load.

Fixes #383.

applet.video.ws2818_output: support different input vs. output pixel size

applet.video.ws2818_output: add support for LEDs other than RGB

applet.video.hub75_output: implement basic HUB75 test pattern generator

README: add comment about applet entrypoints and re-running install

support.plugin: generalize from applet.metadata.

At this point we have at least three subsystems that would benefit
from a plugin mechanism based on entry points that was added to
handle applets:
* Applets. Duh.
* Applet tools. Currently very awkwardly attached to applets even
though they aren't really related.
* Data loggers. `support.data_loggers` depends on `aiohttp` for
a part of its functionality but because there was no way to
express it, a data logger specific work around was added.

This commit lays the foundation for using the same plugin system
for all three.