new vc agnostic veh

gistfile1.py

def get_config(repo, rev=None):
    """Get the config from the veh root.

    We try and work out what version control system is being used from
    the location of the veh config file.

    We currently only support Mercurial and GIT.

    The veh.conf MUST exist in the file system though we might read a
    completly different version of course."""

    repo_root = find_root_with_file(".veh.conf", repo)
    cfgfile = os.path.join(repo_root, '.veh.conf')
    if not pathexists(cfgfile):
        raise ConfigMissing(cfgfile)

    if not rev:
        with open(cfgfile) as fd:
            cfg = ConfigParser()
            cfg.readfp(fd, '.veh.conf')
        return cfg
    else:
        # FIXME: Moar DVCS! Moar!
        repo_command = None
        if pathexists(os.path.join(repo_root, ".git")):
            repo_command = "git show %(rev)s:%(path)s" % {
                "rev": rev,
                "path": path
                }
        elif pathexists(os.path.join(repo_root, ".hg")):
            repo_command = "hg cat -r %(rev)s %(path)s" % {
                "rev": rev,
                "path": path
                }
        
        if repo_command:
            # FIXE we need to mark that this is a verion problem?
            raise ConfigMissing(cfgfile)

        cfgdata = subprocess.check_output(repo_command.split(" "))
        cfg = ConfigParser()
        cfg.readfp(StringIO(cfgdata), '.veh.conf')
        return cfg