file with @internal. The equivalent can be faked using
the Doxygen ENABLED_SECTIONS mechanism. See docs/testserver.dox
to see how this is done. So I make --enable-internal-docs
also set ENABLED_SECTIONS = INTERNAL and then used it
in docs/testserver.dox to decide if it needs to be included.
in the docs directory.
1. Add a new internal document -- testserver.dox -- to describe
how to set up and maintain the dap test server.
2. It moves the internal documentation (internal.dox, indexing.dox,
and testserver.dox) to later in the documentation table of contents.
3. Cleanup the formatting of the internal documents.
4. Cleanup some minor doxygen issues in other files.
