As a Jenkins master administrator, I would like to have all new JUnit test result XML files be compressed (and allow old ones to not be compressed), so that I can:
1) save disk space on the master
2) save disk space on any backups
3) reduce disk-io required for moving disk over volumes
4) reduce disk-io time required while accessing that data

In my experience, these XML files have TONS of repetition, where gzip can cut the disk by a fraction of 25 or 30 times.