Bug 120315 If the display property of an item is set to "none", it doesn't take effect in new pdf emitter.
Description: If the display property of an item is set to "null", it doesn't take effect in new pdf emitter. steps to reproduce: 1. Add a label. 2. Open "properties" view. 3. Set section>Display as "none". 4. Preview in PDF. Expected result: the label disappears. Actual result: the label is still visible.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/css/engine/value/birt/VisibleFormatManager.java
} else {
					String id = sb.toString();
					String s = id.toLowerCase().intern();
					CSSValue v = (CSSValue) values.get(s);
					result.append((v != null) ? v : new StringValue(
							CSSPrimitiveValue.CSS_STRING, id));
				}
			}
			if (lu == null) {
				return result;
			}
			if (lu.getLexicalUnitType() != LexicalUnit.SAC_OPERATOR_COMMA) {
				throw createInvalidLexicalUnitDOMException(lu
						.getLexicalUnitType());
			}
			lu = lu.getNextLexicalUnit();
			if (lu == null) {
				throw createMalformedLexicalUnitDOMException();
			}
		}
	}
	/**
	 * Implements {@link
	 * ValueManager#computeValue(CSSStylableElement,String,CSSEngine,int,StyleMap,Value)}.
	 */
	public CSSValue computeValue(CSSEngine engine, int idx, CSSValue value) {
		return value;
	}
}