Continuation of "Asciidocj integration"

[gillesB]

According to https://github.com/asciidocfx/AsciidocFX/pull/345 the requirements for an Asciidocj integration are:

• [ ] Migration from asciidoctor.js extensions to asciidoctorj extensions
  • [x] chart plugin
  • [ ] math plugin
  • [x] plantuml plugin (but uml must be replaced with plantuml)
  • [x] ditaa plugin (via plantuml block)
  • [ ] tree plugin
• [ ] supporting reveal.js with asciidoctorj
• [x] pdf plugin customization in UI
• [x] switching option from asciidoctorj-pdf to fop by user
• [ ] asciidoctorj should be used in preview and for other backends, like html, epub
  • [x] preview
  • [ ] html
  • [ ] docbook
  • [ ] epub
• [x] Outline feature

The checkboxes mark what is implemented in this PR. As this is my first contribution to this project I did not want to implement everything at once, but ask if I am on the right track before continuing.

As I wanted to reuse as much code as possible, I had to extend AsciidoctorConfigBase a bit. This change is needed because PdfConfigBean needs more properties than AsciidoctorConfigBase provides.

[rahmanusta]

Hi @gillesB , thanks for the PR. It looks a very nice step to move on AsciidoctorJ. I checked the code out and PDF conversion with AsciidoctorJ has worked well. Keep going the awesome work!

[rahmanusta]

@gillesB Reviewing the last commit, it looks perfect!

[rahmanusta]

Hi @gillesB merged changes to asciidoctorj_backend branch, and additionally implemented the tree block processor

[gillesB]

Hi @rahmanusta, thank you for the information. When I continue the work (I do not know when my family allows it) I will base the work on that branch.