Replaced the application plugin with my own tasks.

These use a JAR as a launcher, so that a console window doesn't pop
up on Windows.
Added default tasks to the root project.
Added a task for packaging a binary distribution.
Moved the code to get the version info into the root project.

And made it store the info in a project property.
Changed generatedResourceDir into a local variable.

It doesn't really need to be a property.
Put the version into the name of the distribution archive.

And of the directory within, too. Also, added a "bin" qualifier.
Groovy style fixes.