rename SAXTest package, new is SAX_StAXTest package

rename SAXTest package, new is SAX_StAXTest package.
New name will SAXTest class and StAXTest class.
change describe at package-info.java

add supported StAXTest parser into package-info.java.
complete StAXTest.java

This class demo used StAX parser XHTML file.
add more describe at SAXTest and StAXTest class

add describe at SAXTest and StAXTest class file.