Clock drift vulnerability #25
Description
While we're at it for #23 and #24 , the current implementation is vulnerable to clock drift. If the system clock is moved backwards during the application's run time, there is a risk of generating duplicate IDs.
This should be relatively easy to fix if we're doing the changes outlined in #23, as we can simply check against the previous IDs timestamp, and make sure the current timestamp is no sooner than it.