Rename misleading mojo class

(cherry picked from commit bd0beeb)

tycho-p2-director-plugin/src/main/java/org/eclipse/tycho/plugins/p2/director/DirectorMojo.java → tycho-p2-director-plugin/src/main/java/org/eclipse/tycho/plugins/p2/director/MaterializeProductsMojo.java

@@ -36,7 +36,7 @@
  * </p>
  */
 @Mojo(name = "materialize-products", defaultPhase = LifecyclePhase.PACKAGE, threadSafe = true)
-public final class DirectorMojo extends AbstractProductMojo {
+public final class MaterializeProductsMojo extends AbstractProductMojo {
     private static final Object LOCK = new Object();
 
     public enum InstallationSource {