lei q: -tt marks direct hits as "flagged"

lei q: -tt marks direct hits as "flagged"

This can be used to quickly distinguish messages which were
direct hits when doing thread expansion vs messages that
were merely part of the same thread.

This is NOT mairix-derived behavior, but I occasionally found
it useful when looking at results in an MUA to know whether
a message was a direct hit or not.

This makes "-t" consistent with non-"-t" cases as far as keyword
reading goes.