This implements the nodesbetween method, and it removes the newer method
and replaces it with calls to nodesbetween.
nodesbetween calculates all the changesets needed to have a complete
revision graph between a given set of base nodes and a given set of
head nodes.
#header#
<title>#repo|escape# Changelog</title>
<description>#repo|escape# Changelog</description>
#entries%changelogentry#
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