Start a node.

    CLI Example:

    .. code-block:: bash

        salt-cloud -a start mymachine

def start(name, vmid=None, call=None):
    '''
    Start a node.

    CLI Example:

    .. code-block:: bash

        salt-cloud -a start mymachine
    '''
    if call != 'action':
        raise SaltCloudSystemExit(
            'The start action must be called with -a or --action.'
        )

    log.debug('Start: %s (%s) = Start', name, vmid)
    if not set_vm_status('start', name, vmid=vmid):
        log.error('Unable to bring VM %s (%s) up..', name, vmid)
        raise SaltCloudExecutionFailure

    # xxx: TBD: Check here whether the status was actually changed to 'started'

    return {'Started': '{0} was started.'.format(name)}