contrib/wix/help.wxs

merge: add an internal:merge3 tool

This variant gives access to a feature already present in ``internal:merge``:
displaying merge base content.

In the basic merge (calling ``hg merge``) case, including more context to the
merge markers is an interesting addition.

But this extra information is the only viable option in case conflict from
grafting (, rebase, etc…).

When grafting ``source`` on ``destination``, the parent of ``source`` is
used as the ``base``. When all three changesets add content in the same
location, the marker for ``source`` will contains both ``base`` and ``source``
content. Without the content of base exposed, there is no way for the user
to discriminate content coming from ``base`` and content commit from ``source``.

Practical example (all addition are in the same place):

* ``destination`` adds ``Dest-Content``
* ``base``        adds ``Base-Content``
* ``source``      adds ``Src-Content``

Grafting ``source`` on ``destination`` will produce the following conflict:

  <<<<<<< destination
  Dest-Content
  =======
  Base-Content
  Src-Content
  >>>>>>> source

This that case there is no way to distinct ``base`` from ``source``. As a result
content from ``base`` are likely to slip in the resolution result.

However, adding the base make the situation very clear:

  <<<<<<< destination
  Dest-Content
  ||||||| base
  Base-Content
  ======= base
  Base-Content
  Src-Content
  >>>>>>> source

Once the base is added, the addition from the grafted changeset is made clear.
User can compare the content from ``base`` and ``source`` to make an enlightened
decision during merge resolution.

<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">

  <?include guids.wxi ?>
  <?include defines.wxi ?>

  <Fragment>
    <DirectoryRef Id="INSTALLDIR">
      <Directory Id="helpdir" Name="help" FileSource="$(var.SourceDir)">
        <Component Id="helpFolder" Guid="$(var.helpFolder.guid)" Win64='$(var.IsX64)'>
          <File Name="config.txt" KeyPath="yes" />
          <File Name="dates.txt" />
          <File Name="diffs.txt" />
          <File Name="environment.txt" />
          <File Name="extensions.txt" />
          <File Name="filesets.txt" />
          <File Name="glossary.txt" />
          <File Name="hgignore.txt" />
          <File Name="hgweb.txt" />
          <File Name="merge-tools.txt" />
          <File Name="multirevs.txt" />
          <File Name="patterns.txt" />
          <File Name="phases.txt" />
          <File Name="revisions.txt" />
          <File Name="revsets.txt" />
          <File Name="subrepos.txt" />
          <File Name="templates.txt" />
          <File Name="urls.txt" />
        </Component>
      </Directory>
    </DirectoryRef>
  </Fragment>

</Wix>