Add a maven plugin to check the licence header in java files.

Change-Id: I99e394d4e2cd999768f4d692c12d5e04cb93adc5
Signed-off-by: Jonathan Dumont <jonathan.dumont@all4tec.net>
diff --git a/pom.xml b/pom.xml
index 70340b1..a0b7a1d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -93,6 +93,41 @@
         <version>${tycho-version}</version>
       </plugin>
       
+      <!-- Plugin used to check the license. -->
+      <!-- NB: It's not configured to write the licence header automatically. -->
+      <!-- Usage: mvn licence:check -->
+      <plugin>
+        <groupId>com.mycila</groupId>
+        <artifactId>license-maven-plugin</artifactId>
+        <version>2.11</version>
+        <configuration>
+          <header>${session.executionRootDirectory}/releng/licence/epl.header.txt</header>
+          <useDefaultExcludes>true</useDefaultExcludes>
+          <failIfMissing>true</failIfMissing>
+          <!-- Avoid a strict check as the header comment contains also the contributors. -->
+          <strictCheck>false</strictCheck>
+          <aggregate>true</aggregate>
+          <includes>
+            <include>**/*.java</include>
+          </includes>
+          <excludes>
+            <exclude>**/src/site/**</exclude>
+            <exclude>**/target/**</exclude>
+          </excludes>
+          <properties>
+            <year>2015</year>
+          </properties>
+        </configuration>
+        <executions>
+          <execution>
+            <phase>process-sources</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      
     </plugins>
   </build>