connection with timeout option

About this https://github.com/nrk/phpiredis/issues/31

New option when you create a phpredis_connect
phpiredis_connect($ip [, int $port, int $timeout ] );
$timeout is optionnal and is in millisecond
It's work with phpiredis_pconnect too.

example:
phpiredis_connect('127.0.0.1' , 6379, 20 );

I'd change the actual test to something like:

```php
$redis = create_phpiredis_connection('169.254.10.10', REDIS_PORT, false, 200);
usleep(500000);

--EXPECTF--
Cannot connect to host '169.254.10.10' on port [6379]
```

This kind of test makes more sense in this case. Since the `create_phpiredis_connection()` utility function does a `printf` we should check that output which is not really clean but it works. I'm using `169.254.10.10` here which is the default static IP address in DHCP configurations when the client cannot get an IP from the DHCP server, I guess it's safe for our testing scenario.

Also, maybe we should perform the same test `phpiredis_pconnect()`.