The "dns_TXT_reply" event now uses a "vector of strings" as the final
parameter instead of just a "string" in order to support DNS TXT
resource records that contain multiple character-strings.
The format in which the TXT answers are logged by default is now changed
to be a list of strings of the form `fmt("TXT %d %s", |str|, str)`, one
for each character-string in the RR and delimited by a space (' ')
character.
- Each transaction ID within a connection is now maintained as
a queue of DNS::Info logging records.
- New function added to the queue.bro script to support
peeking at the new gettable item in the queue without removing it.
In response to feedback from Robin:
- rename "ip_hdr" to "ip4_hdr"
- pkt_hdr$ip6 is now of type "ip6_hdr" instead of "ip6_hdr_chain"
- "ip6_hdr_chain" no longer contains an "ip6_hdr" field, instead
it's the other way around, "ip6_hdr" contains an "ip6_hdr_chain"
- other internal refactoring
