bug fix m to msg

[DougAnderson444]

Fixs #9

[DougAnderson444]

Tests are passing now. There seemed to be an issue with the count. When 2010 is added to the multifeed, it's not in the tail so that callback never gets triggered, so the count is one less than was recorded.

The reason it was passing before was the m.seq === m.seq bug made seq always true (even when it was false), which means the callback always fired, even though the insert didn't update the tail.