Renamed "dist" to "stage" in the spirit of what stage is i.e. just stages the files ready for archiving. Dist now depends on stage.
Committing, although this isn't working properly. When I run the following on a demo project:

../../typesafe/Play20/play dist

then I get:

[error] Reference to undefined setting:
[error]
[error]   universal:package-bin from *:dist
[error]

I've tried to mitigate this by adding the packaging plugin as a dependency to the SbtPluginProject (build.scala, L225).

The other thing that I've not been able to work out yet is how to tell the packaging plugin that the target/dist folder is the source of packaging (and not src/universal).