Typo in constant name; variable-name doesn't conform to function signature.

The timeout constant is named "VARNISH_DEFAULT_TIMETOUT" - this should be "VARNISH_DEFAULT_TIMEOUT".

The timeout is used through 'socket_set_option':
socket_set_option($client, SOL_SOCKET, SO_SNDTIMEO, array('sec' => $seconds, 'usec' => $milliseconds));
socket_set_option uses 'usec' which is time in microseconds, not milliseconds. Although the values used in the module are correct, the variable name $milliseconds is potentially misleading to developers.