Updated GWT Version to 2.8.1

Author: kevzlou7979

pom.xml

@@ -109,7 +109,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>gwt-maven-plugin</artifactId>
-                <version>${gwt-maven-plugin.version}</version>
+                <version>${gwt.version}</version>
                 <executions>
                     <execution>
                         <goals>