Milestone 2.3.0 release

1. An extra tabsheet has been added to allow the user to customize the CSS:

   

   Note that the CSS will only be applied to the SVG in this node.

   Thanks to @Steve-Mcl for an in-depth code review and enhancement suggestions!

2. Js event bubble fix: when an event handler is applied to a parent element, but the event (e.g. click) is received on a child element. Then the parent element handler should be called, i.e. the event should bubble upwards from the child element to the parent element.

3. A foreignElement property (with value true) can be specified for command "add_element", when a foreign element needs to be created. In other words to create a standard HTML element, which means a non-SVG element.

4. Replace svg attributes fix: when a "replace_svg" command is injected and attributes are specified for the "svg" tag, then those attributes should be used in the dashboard.

5. It is now possible to trigger a Javascript event handler when an input message arrives:

   

6. When ``msg.topic` has value "custom_msg", then the payload format can be anything. Which means it does not need to contain a "command" or anything else, because the node will ignore the content of this message completely. Such messages can be used in combination with the "input msg" Js event handler (see previous point), to send data to the custom Js event handler code.

7. Some single-click/double-click event handler issues from the previous version have been solved.