DIRTY FIX: Fwd to self() the leftover frame-fragment

Not always, but sometimes that frame-frag was a whole other frame. In
those cases, it was put in the buffer. Next message to be receieved
would displace it, but replace it in the buffer. Etc.
Merge pull request #8 from sanmiguel/mc-fix-intermittent-tests

DIRTY FIX: Fwd to self() the leftover frame-fragment