Headlines per ADOC file should start at level 1, not 2. Adjusting the
level offset for books helps to avoid warnings when including book
chapters, but still allows to also use the chapters as stand-alone
documents.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

The former HTML file was moved up one directory level and converted to
asciidoc format. Therefore, include the ADOC file from the correct
location now.

Alternatively, we could have included the generated HTML from the
aj-build/dist/docs/doc directory, but that would have meant adding a
dependency to the 'docs' module to several other modules for this one
file. Actually, asciidoc has become a widely used and accepted format
for documentation and is human-readable by design. Therefore, it is OK
to include the ADOC file. The important thing is that the licence
information
  - is contained in each published artifact,
  - can be found easily,
  - its content is human-readable.

All these requirements are still met with this change. Arguably, ADOC is
easier to read than HTML and does not even need a web browser.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

- AspectJ Browser (ajbrowser)
- Forte IDE integration
- JBuilder IDE integration
- Emacs integration

All this information was old and outdated. Ajbrowser was removed from
AspectJ a while ago. If the other tools even still exist, any possibly
existing AspectJ support is not part of AspectJ itself.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Some originals have been deleted already. Others, especially the user
guides, still exist in both formats because they have not been
proof-read and probably lots of links do not function as expected. But I
want to see what the files look like directly on GitHun.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>