post/pre-plugins lists defined within processing objects which may have other properties (description). Plugin registry modified to read in that way the configuration file

Activate with this in application_configuration / input :
      "debug": {
        "gadget": "Input_viewDebugJson",
        "type": "object_view",
        "title": "Debug JSON"
      }

expandSchema: Object.create does not clone an object. Also fix a bug deleting properties after copying