modify sample XMLs

*httpCreated1.xml
 remove unused namespace definition.
 change responseCode value from 000 to 200.

*httpRequest1.xml
 remove unused namespace definition.
 remove some elements that does not appear in xsd.
 change replyLimit value from 0 to 1.

*xmppCreated2.xml
 remove unused namespace definition.

*xmppRequest2.xml
 remove unused namespace definition.
 remove some elements that does not appear in xsd.
 change replyLimit value from 0 to 1.
 add from attribute in iq element.

*readme.txt
 fix HTTP post url in curl examples.