Changes to EventStore connection failure handling

Looking for feedback. Thanks again for working on an EventStore php client!

The goal here is to save an additional request each time I load up EventStore and to move the connection exception into the first sendRequest() that is called.

This also provides a way to configure timeout settings for connect/request. Obviously the defaults are not well thought out but I sure wouldn't wait more than 2 seconds for a "local" EventStore :)

Thanks!
Immutable doesn't mean you cannot change settings, you just replace a Configuration object with another one. Abut the IoC, we can easily use a factory method or something like that. Apart from these considerations, I clearly see a very well defined responsibility for the configuration and we should also prevent the EventStore class to be cluttered with too many elements.