Replace jdom 1.1 with another implementation due to 3rd party vulnerability CVE-2021-33814

Current Situation

• Currently the JobScheduler Master uses jdom version 1.1 during its build process to generate C++ code
• A vulnerability affects this version of jdom,
  • see https://cve.mitre.org/cgi-bin/cvename.cgi?name=2021-33814

Mitigation

• jdom is not included with the JobScheduler distribution., therefore there is no threat involved for users of JobScheduler.
• JobScheduler branch 1.x (JS1) is currently replaced by branch 2.x (JS7) that does not make use of jdom.