* service: watchdog logic: for testing purposes allow ping, but do not require pong
* journal:
+ - import and delete pstore filesystem content at startup
- journald: also get thread ID from client, plus thread name
- journal: when waiting for journal additions in the client always sleep at least 1s or so, in order to minimize wakeups
- add API to close/reopen/get fd for journal client fd in libsystemd-journal.