Use pe:jenkins:{deb,mock}_all tasks that do more parallelism

The versions of these jobs introduced in #124 would cause all the cows
or mocks to be built serially on Jenkins. This version of these
tasks will run the builds with more parallelism.
Merge pull request #131 from branan/all_tasks_for_pe

Use pe:jenkins:{deb,mock}_all tasks that do more parallelism