[Seaside] Comments for configuration values

[Keith Hodges]

Dear All,

One of the items lacking documentation in Seaside is the configuration
app. I still dont know what some of it actually does!
I have added the ability to add comments to seaside/config values. If
anyone would like to contribute more comments they would be most welcome.

this code and comments is now available in the Seaside28Jetsam package

Keith