merge.graft: add option to keep second parent
Currently merge.graft re-writes the dirstate so only a single
parent is kept. For some cases, like evolving a merge commit,
this behaviour is not desired. More specifically, this is
needed to fix
issue4389.
Mercurial's documentation is kept in reStructuredText format, which is
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Use the Makefile in this directory to generate the man and HTML pages.