Properly implemented `%ire`, the reply speech type.
Refactored how known messages are accessed.
$% {$lin pat/? msg/cord} ::< no/@ text line
{$url url/purf} ::< parsed url
{$exp exp/cord res/(list tank)} ::< hoon line
+ {$ire top/serial sep/speech} ::< in reply to
{$fat tac/attache sep/speech} ::< attachment
{$inv inv/? cir/circle} ::< inv/ban for circle
{$app app/term msg/cord} ::< app message
