* service resource: Fix no `.service` + systemd bug
This modifies the `enabled?` check to fallback to `sysv_service` in the
event that a `.service` file cannot be found.
For example: On Debian 8.7 the stock apache2 package does not deploy a
`.service` file but deploys a SysV style service. This causes
`systemctl is-enabled` to fail when the service is in fact enabled.
* Remove `cmd_stderr` and clean up `cmd_exit_1`
* Clean up `stderr` assignment using ternary
