Plugin JSON Descriptor file can be included in the plugin
There were several ways to configure an Essentials Plugin to make it show up in the list of Essentials Features. The preferred location of the descriptors is now to include it in the code of the plugin itself. Essentials will scan the classpath for jars and read the scriptor from the jar.
Structure of Repository Snapshots in JSON descriptor has changed
If you specified in the JSON descriptor for an Essentials Plugin that a maven Repository was needed, you may have to update this definition. For the Snapshot part you could only specify the "enabled" element. That has now changed: all elements that can be configured in maven can be specified in the JSON descriptor now too.