Fix signing and tarring

- Sign PE rpms and rpms using the right tasks in the jenkins signing
Because rpms and debs are laid out differently in PE under pkg/ they have a
different sign task to address this. Rather than create a whole extra :jenkins
task for signing PE, we determine which sign task to use based on if we're
building PE

- Add tarball to the list of things done in a pe:jenkins:uber_build
We currently don't explicitly build a tarball in the jenkins uber_build for PE
because we haven't shipped sources this way for PE. Now that we're doing this
as part of the workflow for pe-puppet, and it won't hurt anything to do it for
the other projects, we add it to the list of tasks.