Loads and parses /usbkey/config

def _load_config():
    '''
    Loads and parses /usbkey/config
    '''
    config = {}

    if os.path.isfile('/usbkey/config'):
        with salt.utils.files.fopen('/usbkey/config', 'r') as config_file:
            for optval in config_file:
                optval = salt.utils.stringutils.to_unicode(optval)
                if optval[0] == '#':
                    continue
                if '=' not in optval:
                    continue
                optval = optval.split('=')
                config[optval[0].lower()] = optval[1].strip().strip('"')
    log.debug('smartos.config - read /usbkey/config: %s', config)
    return config