Bug 213671 Expose evaluate() method in IReportContext
Need Engine expose evaluate() method in IReportContext interface, this will be used to evaluate global Javascript expression in case there's no resultset bound to current report item.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/script/IReportContext.java
* @param value
	 */
	void setParameterValue( String name, Object value );
	/**
	 * 
	 * @param name
	 * @return
	 */
	String getParameterDisplayText( String name );
	/**
	 * 
	 * @param name
	 * @param value
	 */
	void setParameterDisplayText( String name, String value );
	/**
	 * 
	 * @return
	 */
	Locale getLocale( );
	
	/**
	 * Get time zone informations.
	 * @return
	 */
	TimeZone getTimeZone( );
	/**
	 * 
	 * @return
	 */