[PATCH 0 of 3 STABLE] bundlerepo: make secret revisions visible, if bundle bases on current local repo

[FUJIWARA Katsunori]

This patch series focuses on the inconsistency between "hg incoming"
and "hg unbundle": "hg incoming" doesn't show the revisions in the
bundle, even though they are restored by "hg unbundle", if they are
descendant of secret ones in local repository.

Patch #1 and #2 are preparation for patch #3.