evolve: add comptability to read old evolvestate files
When a user runs `hg evolve` with old evolve where we used to write evolvestate
the old ways i.e. without using cbor, and faces conflicts, the evolve is
interrupted. If the user updates evolve before completing the evolve, that can
result in traceback as the new evolve cannot read the old evolvestate file.
The previous patch added function to read old evolvestate file and this patch
uses that when we encounter the above mentioned case.
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.