Add more reports to maven site

Add the following additional reports:
- cross-reference report
- API changes report using clirr
- findbugs report
- surefire-report

Run
$ mvn test install site:site site:stage
to generate and stage the site

Also see
https://wiki.eclipse.org/EGit/Contributor_Guide#JGit_3

Change-Id: Ibb6a2e13e128d7728b3c632cc16bf79716dc75f5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

pom.xml

@@ -396,6 +396,21 @@
             </dependency>
           </dependencies>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-surefire-report-plugin</artifactId>
+          <version>2.18.1</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-jxr-plugin</artifactId>
+          <version>2.5</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-project-info-reports-plugin</artifactId>
+          <version>2.8</version>
+        </plugin>
       </plugins>
     </pluginManagement>
 
@@ -495,6 +510,10 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-report-plugin</artifactId>
+      </plugin>
     </plugins>
   </build>
 
@@ -507,6 +526,29 @@
         <configuration>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jxr-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>clirr-maven-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>findbugs-maven-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-report-plugin</artifactId>
+        <configuration>
+          <aggregate>true</aggregate>
+          <alwaysGenerateSurefireReport>false</alwaysGenerateSurefireReport>
+          <reportsDirectories>
+            <reportsDirectories>${project.build.directory}/surefire-reports</reportsDirectories>
+          </reportsDirectories>
+        </configuration>
+      </plugin>
     </plugins>
   </reporting>