[SPEC] Added missing body object in snapshot apis
Use millis for joda DateTimeFormatter.print()

Fixes #4782.
[SPEC] removing deprecated include/exclude for get_source

_source_include/_source_exclude should be used instead
Removed double masterNodeTimeout set in RestPutRepositoryAction
[TEST] fixed error message in REST tests runner
Check ThreadInfo[] for null element if thread are not alive.

If a thread is not alive getting ThreadMXBean#getThreadInfo(long[], int)
places null elemnents in the returned array which are not repected
in the HotTheards API.

Closes #4775