XML解析中的问题

http://www.unicode.org/unicode/faq/utf_bom.html
这里解释了一些规范.
* BOM(Byte order mark):
* 00 00 FE FF = UTF-32, big-endian
* FF FE 00 00 = UTF-32, little-endian
* FE FF = UTF-16, big-endian
* FF FE = UTF-16, little-endian
* EF BB BF = UTF-8
*/