stack: optimize revset used for stack --children
Since that option needs to exclude changesets on the current stack, let's just
use stack.revs (that are cached) for that and skip branch() or topic() revset.
st.revs[0] is the stack base, we don't consider it actual part of stack.
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/