[RFC] Allow names to override chunk variables.

This feels gross and I haven't thought of a better way of doing this
besides adding __hash__ to OrderedDict (if it is decided that is the
best way, then probably needs to be moved into it's own class) but I
would be interested in other peoples opinions on how to achieve these
results?

    ius:
      pkgrepo.managed:
        - humanname: IUS Community Packages for Enterprise Linux 6 - $basearch
        - gpgcheck: 1
        - baseurl: http://mirror.rackspace.com/ius/stable/CentOS/6/$basearch
        - gpgkey: http://dl.iuscommunity.org/pub/ius/IUS-COMMUNITY-GPG-KEY
        - names:
            - ius
            - ius-devel:
                - baseurl: http://mirror.rackspace.com/ius/development/CentOS/6/$basearch

Thanks
Daniel