heptapod-ci: add a script to map evolve branch to mercurial revision for tests
map-hg-rev.sh can be tested using this command:
```sh
for i in $(hg log -T '{branch}\n' | sort -u); do
echo $i $(testlib/map-hg-rev.sh $i)
done
```
syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
^tests/.*\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes
^docs/training/graphs/
^docs/training/html/
^docs/training/index.html
^docs/training/graphviz-images/
^docs/training/img/
^docs/training/output/
^docs/training/pandocfilters/