tests: add more tests related to stabilization of orphaned merge commit This patch more tests related to stabilization of orphaned merge commit. Stabilization of a merge changeset with both the parents is not supported right now and prints a message on how to do that. Maybe we should do that internally as a part of `hg evolve` but I need to think about this.

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/