evolve: fix confusion in branch heads checking logic when topic in play To provide some context, when topics are in play the branchmap cache we store contains the branch info of a rev as "branch:topic" format IIUC. Assuming that is right, now in present code we don't actually cover this part that "when looking for branch heads where we also have active topic we should look for branch='branch_name:topic' instead". And we get wrong branch heads as a result. This patch make sure that we pass right candidate to find branch heads using branchmap.branchheads() by overriding the localrepo.branchheads() Changes in test file reflect the fixed behavior.

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.