stack: handle external-children just like other states
This also fixes color labels: previously when external-children was combined
with another state, --color=debug would show something like:
[topic.stack.index topic.stack.index.current - external-children|s4]
Now there is a separate label for each state.
exclude contrib
recursive-exclude contrib *
exclude hgext3rd/evolve/hack
recursive-exclude hgext3rd/evolve/hack *
exclude hgext3rd/evolve/legacy.py
exclude Makefile
exclude tests/test-drop.t
exclude tests/test-inhibit.t
exclude tests/test-oldconvert.t
exclude docs/tutorial/.netlify
include COPYING
include docs/figures/hgview-example.png
include docs/makefile
include docs/*.py
include docs/README
include docs/*.rst
include docs/static/*.svg
include docs/tutorials/*.t
include hgext3rd/__init__.py
include hgext3rd/evolve/*.py
include hgext3rd/evolve/thirdparty/*.py
include hgext3rd/topic/*.py
include hgext3rd/topic/README
include MANIFEST.in
include README
include CHANGELOG
include setup.py
include tests/*.py
include tests/*.sh
include tests/testlib/*.sh
include tests/*.t
recursive-include docs/tutorial *.rst
recursive-include docs/tutorial *.css
include docs/tutorial/standalone.html
recursive-include docs/tutorial *.js
recursive-include docs/tutorial *.md
recursive-include docs/tutorial *.py
recursive-include docs/tutorial *.sh
recursive-include docs/tutorial *.t
prune debian
recursive-include docs/figures *.svg