The base class of all Preference classes. A preference class provides a wrapper
	 * around one or more SWT widgets and handles the input of values for some key.
	 * On each change, the new value is written to the map and the listeners are notified.
The base class of all Preference classes. A preference class provides a wrapper
	 * around one or more SWT widgets and handles the input of values for some key.
	 * On each change, the new value is written to the map and the listeners are notified. | ModifyDialogTabPage.java