A major feature release with a significant API improvement!

This update does not involve any BC breaks, but we figured the new API provides significant features that warrant a major version bump. Existing code will continue to work without changes, but you're highly recommended to consider using the new lazy connections as detailed below.

• Feature: Add new createLazyConnection() method to only connect on demand and implement "idle" timeout to close underlying connection when unused. (#87 and #88 by @clue)

  // new
  $connection = $factory->createLazyConnection($url);
  $connection->query(…);
  

  This method immediately returns a "virtual" connection implementing the ConnectionInterface that can be used to interface with your MySQL database. Internally, it lazily creates the underlying database connection only on demand once the first request is invoked on this instance and will queue all outstanding requests until the underlying connection is ready. Additionally, it will only keep this underlying connection in an "idle" state for 60s by default and will automatically end the underlying connection when it is no longer needed.

  From a consumer side this means that you can start sending queries to the database right away while the underlying connection may still be outstanding. Because creating this underlying connection may take some time, it will enqueue all oustanding commands and will ensure that all commands will be executed in correct order once the connection is ready. In other words, this "virtual" connection behaves just like a "real" connection as described in the ConnectionInterface and frees you from having to deal with its async resolution.

• Feature: Support connection timeouts. (#86 by @clue)