evolve: continue conflicted relocation content-divergence
This patch adds logic to continue an conflicted content-divergence resolution
which was interrupted while relocating one of the divergent commits.
The tests shows the there is some mishandling of copies internally which will be
fixed in next patch.
. $TESTDIR/testlib/pythonpath.sh
cat >> $HGRCPATH << EOF
[extensions]
docgraph=
EOF