Bug 153378 [Regression]Label text won't show up when the text key is not found
Steps to reproduce: 1.Add a label, set text to "aaa" 2.Add a resource file "a" to the report, add a text key "k1" which is not in the a.properties to the label 3.Preview in Web Viewer Expected result: Label display "aaa" when the text key is not found Actual result: Nothing in preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/ReferencableStructure.java
* not.
	 * 
	 * @param memberName
	 *            the member name to check
	 * @return true if the member with the given name is referencable, otherwise
	 *         false
	 */
	public abstract boolean isReferencableProperty( String memberName );
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.Structure#getIntrinsicProperty(java.lang.String)
	 */
	protected Object getIntrinsicProperty( String propName )
	{
		if ( LIB_REFERENCE_MEMBER.equalsIgnoreCase( propName ) )
			return this.libReference;
		assert false;
		return null;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.Structure#getProperty(org.eclipse.birt.report.model.core.Module,
	 *      org.eclipse.birt.report.model.metadata.PropertyDefn)
	 */
	public Object getProperty( Module module, PropertyDefn propDefn )
	{
		assert propDefn != null;