(#22660) Revert Fedora 17+ agent service name to "puppet" from "puppetagent".

Due to pull request 1166, in the fedora 17+ transition to systemd, the puppet
agent service was inadvertantly renamed from "puppet" to "puppetagent".

- in specfile, move systemd service and unit file names back to "puppet" from erroneous "puppetagent"
- Add symlink to puppetagent unit file for compatibility with current bug
- Alter package removal actions to deactivate and stop both service names
- rename unit file in source tree to correspond with this