Code cleanup: Replace swing listener with adapters; Added SuppressWarnings for Swing based classes.

These patches provide some minor code cleanup.

The first patch replaces various anonymous swing listener with their appropriate adapter counterpart. This allows to omit empty methods, which would be required by the implementation of the respective interface.

The second patch adds the @SuppressWarnings("serialize") annotation for classes, that shouldn't be serialized but implement the Serializable interface like, for example, the swing widgets.