- Flumotion messages should be able to link to the documentation
- If yelp is present on the system, and the documentation Docbook/XML is
  present too, we can use yelp to open the documentation:
  yelp ghelp:///usr/share/flumotion/manual/xml/manual.xml?section-system-setup
- If yelp is not present on the system, or the docs are not present, we
  can use a standard browser to open the documentation URL:
http://www.flumotion.net/doc/flumotion/manual/html/chapter-configuration.html#section-system-setup
- The docs on the flumotion website should be versioned, so that the message
  can link to a correct version of the docs
- Hence, the message should have the version of Flumotion encoded in it
  to link to the docs
- On the local system, we will only have one specific version of the docs.
  It may not match the version of the manager's documentation.
- We could bundle documentation and transfer it from the manager, to ensure
  it is for the right version.

PROPOSAL
--------
- A link target:
  - is uniquely identified by:
    - the project (from the perspective of the message-generating code)
    - the project's version
      (again, the version of the code that generates the message;
       a 0.4.1 worker running a check from a 0.4.2 manager should tag
       the link target with 0.4.2)
    - the "book" name (for example "manual", "faq", ...)
    - an id (which is the DocBook/XML id inside the book)
    (- a localization tag, in the future ?)
  - also contains:
    a descriptive text
  - may additionally need the name of the parent chapter/section to assist
    linking to the online html version

- When the admin needs to show a link as part of the message:
  - if yelp is available:
    - if there is local documentation installed for the right version,
      use yelp ghelp:// to display it locally
    - if there isn't, try to get a documentation bundle for the project
      and version from the manager, and display
  - if yelp is not available, or getting a local copy fails:
    use a browser to show the link.  The base URL for docs should be
    identified as part of the project.  Under that link, there should be
    a set of directories with the versions

