FlexChartEditableAnnotations
------------------------------------------------------------------------------
This sample shows how to display and edit annotations in FlexChart. 

Following operations of editing annotations are supported in this sample:

1. You can click the buttons "A|D|R" to choose Absolute, DataCoordinate or Relative AnnonationAttachment respectively for new Annotations.
2. You can click on one of the Annotation symbol in the Toolbar to choose a pre-defined Annotation type. 
After selecting the symbol, click and drag on the chart's PlotArea to add the selected Annotation type.
3. You can double-click an Annotation to edit its text.
4. You can drag and move annotations around the chart. Uncheck the 'AllowMove' button to disable moving Annotations.
5. You can delete a selected Annotation by pressing the 'Delete' Key or by using the FlexChart ContextMenu.