We set up hudson to have some of our projects use 'private' repositories, where the repository is a part
of the build workspace. This causes all dependencies to be re-downloaded, and accurately shows what
would havppen if a 'new developer' started work. This checks that there is nothing that is lying around
in a repository that isn't properly specified in a repository.

to do this, we add something like
-Dmaven.repo.local=E:\tomcat-home\.hudson\jobs\Nightly_US\workspace\trunk\localRepository
to the maven options. But this relies on knowing where the workspace is going to be on disk, so only
people that understand that can get it set up.

It'd be spiffy to have a 'use private repository' button on the m2 settings, and a 'clear repository every
build' option.

Additionally, because m2 projects can't be run in parallel (because local repositories aren't thread safe),
we only ever have 1 project build at once. But for projects that 'use private repository', multiple could
be built at once - this would be a useful option (only build private repositories in parallel).