Bug 140542 label can't be displayed without resource file or unmatched key
Steps to reproduce: 1.New a report, add a lable with text "aaa" 2.Add a resource file for the report, set key to "key1", value to "actuate", apply the value to the label 3.Clear the resource file in Property Editor->General->Resource File (or change the key to "abc") 4.Preview the report Expected result: 1.Display label text "aaa" on preview or 2.Give a warning message to say resource file is not found or unmatched key Actual result: Nothing displays on preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* 
	 * @param resourceKey
	 *            resourceKey of the user-defined message where the translation
	 *            is defined in.
	 * @param locale
	 *            locale for the translation. Locale is in java-defined format(
	 *            en, en-US, zh_CN, etc.)
	 * @return the <code>Translation</code> that matches. return null if the
	 *         translation is not found in the report.
	 */
	public Translation findTranslation( String resourceKey, String locale )
	{
		return translations.findTranslation( resourceKey, locale );
	}
	/**
	 * Returns if the specified translation is contained in the translation
	 * table.
	 * 
	 * @param trans
	 *            a given <code>Translation</code>
	 * @return <code>true</code> if the <code>Translation</code> is
	 *         contained in the translation talbe, return <code>false</code>
	 *         otherwise.
	 */
	public boolean contains( Translation trans )
	{
		return translations.contains( trans );
	}
	/**
	 * Returns the whole collection of translations defined for the report