setting marks for all levels between current speaker and next speker (on
conversation level raise)
and for 'count from' - check higher levels for a mark for potential use
so that 'extend' raised to 'meta' would still count 'next topic' as
going from previously 'extending' person
now going down by many levels - starts from marked person due to 'count from' logic
that uses marks from higher level if current level doesn't have a mark
but also going down by 1 step keeps the marks until we return to initially diverged
conversation layer
efim