Pass on registration trace events to clients
Additional support for remote tracing
Back out change to the granularity of timestamps in log messages
Explicitly enable the initial tracer process
Cosmetic
Fix a bug in the built-in log file tracer

Using `matchAnyIf` we managed to fool the type checker into passing a
Message instance into a predicate pattern matching on TraceEvent.
Allow users to set initial trace flags via environment variables
Merge heads