Bug 153896 Improve the performance of BIRT datetime-converting
The current datetime converting algorithm in birt.core, xml&flatfile ODA implementations are not efficient enough.This is because we use java's SimpleDateTimeFormatter to parse ISO8601 compatible date/time values. We should write our own datatime string parser for ISO8601 datetime format.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
if ( resultDate == null )
		{
			throw new BirtException( pluginId,
					ResourceConstants.CONVERT_FAILS,
					new Object[]{
							source.toString( ), "Date"
					},
					resourceBundle );
		}
		
		return resultDate;
	}
	/**
	 * A temp solution to the adoption of ICU4J in BIRT. It is a simple
	 * delegation to toDateWithCheck( String, Locale ).
	 * 
	 * @param source
	 * @param locale
	 * @return Date
	 * @throws BirtException
	 */
	public static Date toDateWithCheck( String source, Locale locale )
			throws BirtException
	{
		return toDateWithCheck( source, ULocale.forLocale( locale ) );
	}
	/**
	 * Convert string to date with check.
	 * JDK may do incorrect converse, for example:
	 * 		2005/1/1 Local.US, format pattern is MM/dd/YY.