Shawn Pearce
81f9c18433
Define MonotonicClock interface for advanced timestamps
MonotonicClock can be implemented to provide more certainity about
time than the standard System.currentTimeMillis() can provide. This
can be used by classes such as PersonIdent and Ketch to rely on
more certainity about time moving in a strictly ascending order.
Gerrit Code Review can also leverage this interface through its
embedding of JGit and use MonotonicClock and ProposedTimestamp to
provide stronger assurance that NoteDb time is moving forward.
Change-Id: I1a3cbd49a39b150a0d49b36d572da113ca83a786