Implement a technical solution to track translations on a file base

[fsundermeyer]

• needs to work for ASCIIDoc and DocBook
• needs to make it possible to track several languages per file

[tomschr]

Are the docmanager tags not appropriate anymore?

[ghost]

The main issue is that we can only do translation=yes|no. But we want/need per-file language-dependent information, i.e. translation=[language1],[language2],... -- discussed here