GH-998: Fix Reporter::conn_weird() to handle expired connections

This introduces a new sampling state-map for expired connections to fix
segfaults that previously occured when passing in a `connection` record
to `Reporter::conn_weird()` for which the internal `Connection` object
had already been expired and deleted.  This also introduces a new event
called `expired_conn_weird`, which is similar to `conn_weird`, except
the full `connection` record is no longer available, just the `conn_id`
and UID string.

src/Timer.cc

@@ -19,6 +19,7 @@ const char* TimerNames[] = {
 	"ConnectionExpireTimer",
 	"ConnectionInactivityTimer",
 	"ConnectionStatusUpdateTimer",
+	"ConnTupleWeirdTimer",
 	"DNSExpireTimer",
 	"FileAnalysisInactivityTimer",
 	"FlowWeirdTimer",