Bug 212505 Use default script ID to skip script debugging
In Dte side, when compile or evaluate java script, it would pass in a script source id. This kind of id is currenlty used by report script debugger. So to skip redundant processing for such kind of internal script evaluating, dte need pass in a default ID, which is defined as ScriptExpression.defaultID. If this id is already used for particular meaning and it can not pass in the default ID, we need define them as public constants and let script debugger check and skip them as well.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ExecutionContext.java
*/
	private IReportContent reportContent;
	/**
	 * the current executed design.
	 */
	private ReportItemDesign design;
	/**
	 * The current content element to be executed or loaded
	 */
	private IContent content;
	
	/**
	 * the current opened result set 
	 */
	private IBaseResultSet[] rsets; 
	/**
	 * A stack of handle objects, with the current one on the top
	 */
	private Stack reportHandles = new Stack( );
	/**
	 * total page
	 */
	private long totalPage;
	/**
	 * current page number
	 */
	private long pageNumber;
	/**
	 * A list of script errors found in onPrepare. These will be added to the
	 * IReportContent, when one is available