Viewer Doxygen

There is an experimental set of documentation pages for the viewer source generated using Doxygen.

The use of Doxygen for documenting the code is called for in the Coding Standard, but has been unevenly employed. Fixing this when you touch something is a good thing, and results in much karmic credit.

Note: The pages linked above are updated manually by Oz when the mood comes on him to do so. If they are stale, then nicely worded reminders, especially in the context of potential open source contributions, will probably cause them to be updated.