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/api/util/ParameterValidationUtil.java
*             if the value is invalid
	 */
	static final Date doVidateDateTime( String value, ULocale locale )
			throws ValidationValueException
	{
		try
		{
			return DataTypeUtil.toDate( value, locale );
		}
		catch ( BirtException e )
		{
			throw new ValidationValueException( value,
					PropertyValueException.DESIGN_EXCEPTION_INVALID_VALUE,
					DesignChoiceConstants.PARAM_TYPE_DATETIME );
		}
	}
	/**
	 * Validates the input value at the given locale. The format is: general
	 * number.
	 * 
	 * @param dataType
	 *            the data type
	 * @param value
	 *            the value to validate
	 * @param locale
	 *            the locale information
	 * @return the double value if validation is successful
	 * @throws ValidationValueException
	 *             if the value is invalid
	 */