Grabs a message someone says, and adds it to the quotegrabs database. You may grab multiple nicks/messages in one quotegrab by separating the arguments with a plus sign (the nicks need not be different -- you can grab multiple messages by the same nick by specifying a different history for each grab).
You can use the [recall](#recall) command to test the arguments before grabbing (please use a private message).
Usage: `grab <nick> [history [channel]] [+ ...]`
where [history] is an optional argument regular expression used to search message contents;
e.g., to grab a message containing the text "pizza", use: grab nick pizza
<bob> Clowns are scary.
<pragma-> grab bob clowns
<PBot> Quote grabbed: 1: <bob> Clowns are scary.
<!---->
<alice> Please put that in the right place.
<bob> That's what she said!
<pragma-> grab alice place + bob said
<PBot> Quote grabbed 2: <alice> Please put that in the right place. <bob> That's what she said!
<!---->
<charlie> I know a funny programming knock-knock joke.
<charlie> Knock knock!
<charlie> Race condition.
<charlie> Who's there?
<pragma-> grab charlie knock + charlie race + charlie there
