StatusCommand#setWorkingTreeIt should return 'this'

All setters for JGit API commands return the command instance, follow
the builder pattern.

Change-Id: Id2bbc3f1300bb179887c4d2d6dd72925bde55f24
Signed-off-by: Kevin Sawicki <kevin@github.com>

org.eclipse.jgit/src/org/eclipse/jgit/api/StatusCommand.java

@@ -95,8 +95,11 @@ public class StatusCommand extends GitCommand<Status> {
 	 * method is not called a standard {@link FileTreeIterator} is used.
 	 *
 	 * @param workingTreeIt
+	 *            a working tree iterator
+	 * @return {@code this}
 	 */
-	public void setWorkingTreeIt(WorkingTreeIterator workingTreeIt) {
+	public StatusCommand setWorkingTreeIt(WorkingTreeIterator workingTreeIt) {
 		this.workingTreeIt = workingTreeIt;
+		return this;
 	}
 }