Fix/update model documentation for new models in release 3.0

[butler]

While all the model documentation is now rewritten in ReST, we cannot easily render that until we move to wx3.0 so this will be for next release. In the meantime the new models whose documentation was in ReST only will need to be added to the old html file.

NOTE: the new prism models documentation seems to use the display box that is used for custom models and displays only parameter information in a not very helpful manner. This needs to be fixed before the release.

[butler]

Peter finished this - looks good