INT-2768 Add XSLT Transformer Factory Class Name

Add the ability to inject the class name of the xslt transformer
implementation.

https://jira.springsource.org/browse/INT-2768

-add @author to java docs
-updat copywrite year to current year

add new test and check for class name that it exists.

-fix xslt payload transformer and test for unknown class name, will
now default to the jre default transformer.

spring-integration-xml/src/main/resources/org/springframework/integration/xml/config/spring-integration-xml-2.2.xsd

@@ -237,6 +237,19 @@
 							</xsd:appinfo>
 						</xsd:annotation>
 					</xsd:attribute>
+					<xsd:attribute name="transformer-factory-class" type="xsd:string" use="optional">
+						<xsd:annotation>
+							<xsd:documentation><![CDATA[
+								A fully qualified class name to a transformer factory
+								class that overrides the current JVM default.								
+							]]></xsd:documentation>
+							<xsd:appinfo>
+								<tool:annotation kind="ref">
+									<tool:expected-type type="javax.xml.transform.TransformerFactory"/>
+								</tool:annotation>
+							</xsd:appinfo>
+						</xsd:annotation>
+					</xsd:attribute>
 				</xsd:extension>
 			</xsd:complexContent>
 		</xsd:complexType>