Merge pull request #1733 in SNORT/snort3 from ~SMINUT/snort3:rna_update_timeout to...

Merge pull request #1733 in SNORT/snort3 from ~SMINUT/snort3:rna_update_timeout to master

Squashed commit of the following:

commit e082dd186ee53898cb90b31d7b426cd277afd2f1
Author: Silviu Minut <sminut@cisco.com>
Date:   Thu Sep 5 12:41:00 2019 -0400

    rna: generate an RNA_EVENT_CHANGE when a host is seen after the last log event and the current time is past the update timeout.

    rna: lock when returning last_seen and last_event in host tracker and add peg counts for RnaIdleEventHandler.

    rna: pass cond_var to the rna log functions, as per snort 2.

    rna: make generation of a CHANGE_HOST_UPDATE event from idle, configurable.

    rna: change RnaLoggerEvent::cond_var from time_t to void* because SfUnified2LoggerRNA::rna_serialize() already takes a void* as cond_var.

    rna: pass host tracker IP address rather than NULL when calling generate_change_host_update from idle.

    rna: supress unused variable message in RnaIdleEventHandle::handle().

    rna: address reviewers' comments.