Add up and completion of javadoc

Author: JeanDeboutGat

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/component/DuplicateRemover.java

@@ -4,7 +4,7 @@
 import us.codecraft.webmagic.Task;
 
 /**
- * Remove duplicate requests.
+ * Remove duplicate requests.</br>
  * @author code4crafer@gmail.com
  * @since 0.5.1
  */

webmagic-core/src/main/java/us/codecraft/webmagic/selector/BaseElementSelector.java

@@ -7,6 +7,8 @@
 import java.util.List;
 
 /**
+ * Base selector for html elements.
+ * 
  * @author code4crafter@gmail.com
  * @since 0.3.0
  */

webmagic-core/src/main/java/us/codecraft/webmagic/utils/NumberUtils.java

@@ -1,6 +1,8 @@
 package us.codecraft.webmagic.utils;
 
 /**
+ * Numbers comparison utilility for schedule priority
+ * 
  * @author yihua.huang@dianping.com
  */
 public abstract class NumberUtils {

webmagic-core/src/main/java/us/codecraft/webmagic/utils/WMCollections.java

@@ -6,6 +6,8 @@
 import java.util.Set;
 
 /**
+ * WebMagic collections builders
+ * 
  * @author code4crafter@gmail.com
  *         Date: 16/12/18
  *         Time: 上午10:16