'Start a node.
:param node: Node to start.
:type node: :class:`libcloud.compute.base.Node`
:param ex_avoid: A list of other server uuids to avoid when
starting this node. If provided, node will
attempt to be started on a different
physical infrastructure from other servers
specified using this argument. (optional)
:type ex_avoid: ``list``'

def ex_start_node(self, node, ex_avoid=None):

    params = {}
    if ex_avoid:
        params['avoid'] = ','.join(ex_avoid)
    path = ('/servers/%s/action/' % node.id)
    response = self._perform_action(path=path, action='start', params=params, method='POST')
    return (response.status == httplib.ACCEPTED)
