Plugin Repositories to allow optional and third party plugins.

[farion]

Currently CorreoMQTT is able to be extended by plugins. There is a list of plugins that are installed automatically from urls. And it is possible to copy plugin-jars manually to the jars-Folder.

With this approach it is not possible to have plugins available that can be installed via click in the UI.

The idea to solve this is as follows:

CorreoMQTT maintains a list of plugin-jsons as plugin repositories. These are stored in the configuration and can be changed via configuration dialog. Per default there is one registry added already: https://github.com/EXXETA/correomqtt-pluginrepo/blob/master/plugins-repository-{version}.json

On start CorreoMQTT will also check https://github.com/EXXETA/correomqtt-pluginrepo/blob/master/mandatory-plugins-{version}.json which holds a list of mandatory plugins. These plugins will be installed automatically (if possible).

Also CorreoMQTT will check all repositories during start and updating plugins if possible. There is also an "Update" button in the plugin dialog to trigger this.

The plugin dialog will be extended. It shows all plugins from the repository, not only the installed ones. If a plugin is installed, it will have an "Uninstall" and an "Disable" button (no checkmarks) and except it is one of the mandatory plugins. If the plugin is not installed it will have an "Install" button. Some of the existing informations will be visible if the plugin is installed only. There is also a column where the repository is mentioned.

If a plugin id is used twice, this will cause an error message. The message will provide the option to reset the repository settings (which will set the list of repositories to the default one only).