* Updated Connections handling
- The ConnectionPool.getConnection method now always returns a connection
- The ConnectionPool.update mehtod now cleans the dead list
- Deprecated the NoLivingConnectionsError
* Updated test
* Updated docs
* The NoLivingConnectionsError can still happen if the filter/selector returns no nodes
* Updated test
* Updated docs
* Catch undefined connections as well
* Updated test
* Updated ApiError type def