evolve: fix the broken behaviour on div resolution in relocation case
In content divergence resolution, I see that when "relocationreq" is
True which means both the cset are on different parent and relocation
is required. In this case when "divergent" is the one who is behind
the "other" cset in DAG, we swap them. At this point one thing we
missed is to update the evolvestate['divergent'].
Because of this in continue case we didn't get the right value
of obsmarkers creation.
In this patch I added the code to update the evolvestate when we swap
them.
Now as we know "divergent" and "other" can be swapped in some cases,
it is better to store the intial divergent separately in evolvestate
which is evolvestate['orig-divergent'] and later this value is used
to update the evolvestate['replacements'] which is the track of
revisions which has been resolved.
Changes in tests demonstrate the fixed behaviour.