Bug 125963 reportContext.getConfigVariableValue() always returns null
The getConfigVariableValue() method of reportContext always returns null. At least it does with the variables I tried, "BIRT_HOME" and "java.version", and "user.name".
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/script/IReportContext.java
* later. It is persisted between phases, i.e. between generation and
	 * presentation.
	 */
	void setPersistentGlobalVariable( String name, Serializable obj );
	/**
	 * Remove an object from report document scope.
	 */
	void deletePersistentGlobalVariable( String name );
	/**
	 * Retireve an object from report document scope.
	 */
	Object getPersistentGlobalVariable( String name );
	/**
	 * Finds user-defined messages for the current thread's locale.
	 */
	String getMessage( String key );
	/**
	 * Finds user-defined messages for the given locale.
	 */
	String getMessage( String key, Locale locale );
	/**
	 * Finds user-defined messages for the current thread's locale
	 */
	String getMessage( String key, Object[] params );
	/**
	 * Finds user-defined messages for the given locale using parameters
	 */
	String getMessage( String key, Locale locale, Object[] params );
}