Utility classes for the server tools framework.

PingThread is a utility class for pinging a server to determine if it is running and updating the server's state.

SocketUtil contains utility methods for determining if ports are free and whether a given hostname is a local hostname.

The four XXXAdapter classes are implementations of server tools listener interfaces with the method bodies stubbed in; they can be subclassed by clients who only want to implement a single listener interface method.

ServerPort, Task, and TaskModel are standard implementations of other interface classes.