It would be nice if the commands available in flogtool (dump, tail, etc) could be used as subcommands from a different tool, like the 'tahoe' or 'buildbot' driver. So running 'tahoe flogtool tail' should do the same thing as running 'flogtool tail'.
This would be most useful when that other tool is bundled via py2exe or py2app. In that environment, the 'flogtool' executable isn't available, but the 'tahoe' one is.
To do this, we need to split out the dispatch function, and make the usage.Options classes available for import.
