HSEARCH-1494 &  HSEARCH-1092

Addresses the above issues.

It introduces `IndexedEmbedded#includeEmbeddedObjectId` as flag to explicitly control the embedded object id. If the id is explicitly listed via `includePaths` it still gets included. I think this approach had so far most support.

What is not addressed yet, is whether the default for the `IndexedEmbedded#depth` parameter should change to 0. However, this should probably be addressed in a separate issue anyways.


@hferentschik The issues you've pointed out are important ones, and certainly areas I'm going to work to improve in Asciidoctor. However, it's mostly a difference in the generated output and that can be improved at any time and in any way. For instance, global numbering of examples can easily be changed.

What we do need to improve sooner rather than later is that any display-related content is factored out of the AsciiDoc source. For instance, it shouldn't be necessary to refer to an example by number. Instead, the example should be referenced only by its id, than the output can add the "Example N" prefix where necessary. That's something currently missing in AsciiDoc, so it's high priority.