rebase: don't rebase obsolete commit whose successor is already rebased
This patch avoids unnecessary conflicts to resolve during rebase for the users
of changeset evolution.
This patch modifies rebase to skip obsolete commits if they are being rebased on
their successors.
It introduces a new rebase state 'revprecursor' for these revisions that are
being skipped and a new message to inform the user of what is happening.
This feature is gated behind the config flag experimental.rebaseskipobsolete
When an obsolete commit is skipped, the output is:
not rebasing 14:9ad579b4a5de "I", already in destination as 17:fc37a630c901 "K"
<tr>
<td class="age">{date|rfc822date}</td>
<td class="author">{author|person}</td>
<td class="description">
<a href="{url|urlescape}rev/{node|short}{sessionvars%urlparameter}">{desc|strip|firstline|escape|nonempty}</a>
{inbranch%changelogbranchname}{branches%changelogbranchhead}{tags%changelogtag}{bookmarks%changelogtag}
</td>
</tr>