help: fix keyword search result formatting
This patch fixes the broken formatting of keyword search results. Some blank
lines were missing from the RST markup, which caused markup to be printed.
help: drop -a from heads syntax summary (
issue3483)
revlog: add optional stoprev arg to revlog.ancestors()
This will be used as a step in removing reachable() in a future diff.
Doing it now because bryano is in the process of rewriting ancestors in
C. This depends on bryano's patch to replace *revs with revs in the
declaration of revlog.ancestors.