Version control repository manager

The mr(1) command can checkout, update, or perform other actions on a set of repositories as if they were one combined respository. It supports any combination of git, svn, mercurial, bzr, darcs, cvs, vcsh, fossil, and veracity repositories. It supports extensions which in turn can use more version control systems. It is configurable via shell scripting. Some examples of things it can do include: * Update a repository no more frequently than once every twelve hours. * Run an arbitrary command before committing to a repository. * When updating a git repository, pull from two different upstreams and merge the two together. * Run several repository updates in parallel, greatly speeding up the update process. * Remember actions that failed due to a laptop being offline, so they can be retried when it comes back online. This package also includes the webcheckout(1) command.