evolve: return the new replacement node to be stored in evolvestate While resolving phase-divergence, we can end up obsoleting the phase-divergent commit in favor of the public commit. Before this patch we return the node of public commit to store as a replacement of the phase-divergent commit. The above will not cause any problem till the time we use `hg evolve --abort` on an interrupted evolve which tries to strip the replacement nodes because it thinks that the replacements nodes are the ones which are created during the resolution and are new. Since we will be stripping a public node, `evolve --abort` will error out saying cannot strip public changeset, unable to abort evolve which is bad. We should make sure, replacements should only consist of new nodes formed. If the instablity is resolved by obsoleting in favour of old changeset, we should not store the old changeset in replacements in evolvestate.

Doc is generated with sphinx.

You can generate the doc with:

```
make
```

# Tutorials

For updating the tutorials, you need to have the docgraph extension installed
(https://pypi.python.org/pypi/hg-docgraph).

Then run the test-topic-tutorial.t and test-tutorial.t to update the output if
needed.

You'll need the dot binary (likely installed by the graphviz package in your
package manager) in order to have graphviz graphs rendered in the html output.

Simply run make in the docs directory should takes care of the conversion of
the tutorial .t files into .rst files. Then sphinx should do the rest of the
jobs by rendering graphviz graphs.