topic: improve the revset used to return name->nodes mapping The 'topic' version already filters public changeset out, and skipping 'changectx' creation will helps performance.

syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes