evolve: add a `--abort` flag for `hg evolve` command This patch adds a new flag `--abort` to `hg evolve` command which will abort the interrupted evolve going on undoes the changes created by the evolve command till now. The changes are bookmark movements, creation of evolved commits, obsolete the old commits in favor of evolved commits. In case when user changed things while the interrupted evolve, like did some actions which created a new commit on top of evolved commits, or changed phase of evolved commits to public, the evolve fails to abort as we should not strip out the new commit formed by user neither we can strip the public changeset. The abort fails and tell user to use `hg evolve --stop` instead. Right now bookmark movement is broken, and will be fixed in upcoming patches. Tests are added for the new flag.

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.