Memo delivered unnecesarily

<marcog> tibid ask Taejo do you have the test data for the itc?
<tibid> marcog: Righto
<Taejo> marcog: not sure if I'm supposed to distribute it
<tibid> Taejo: By the way, marcog on shadowfire told me "ask Taejo do you have the test data for the itc?" 55 seconds ago

Perhaps we could avoid doing this by not passing on the memo if the recipient is in the channel when it was sent, and less than a certain amount of time (and dialog) has elapsed since.