Was converted to reStructuredText / Sphinx in commit
8a689e68

Not yet wired to the protocol.

Consume the ConstBuffer instead of iterating it.  This will allow
adding more complex parsers.

Having this as one-byte integer actually adds overhead and saves no
memory due to padding.

Eliminate duplicate code.

Migrating from DocBook to Sphinx.  Editing XML is really too
cumbersome.

This is an experimental draft.  More needs to be done.