After some readings and some testings it looks like Mercurial should be a
good candidate for this Mojo.
CVS is not appropriate, since we don't have a revision of the repository but
a revision of a file.
I don't know about the ohers SCMs, but as I have described in the
documentation we need to have comments per revision of the repository and
listable tags elements.
I have provided my own provider for svn since the subversion implementation
of maven-scm doesn't support XML output, which is far easier to parse.
Emmanuel
