Create Folder, HelpCallback and MenuCallback.

Folder was created by looking at the new UIProvider. HelpCallback and
MenuCallback are interfaces pulled out of MenuHandler.

Change-Id: Ib4f1f9712508f9579c14a3319ec5a421cf07bcaf
diff --git a/src/com/android/mail/providers/UIProvider.java b/src/com/android/mail/providers/UIProvider.java
index 78e93c4..2e4af20 100644
--- a/src/com/android/mail/providers/UIProvider.java
+++ b/src/com/android/mail/providers/UIProvider.java
@@ -200,7 +200,7 @@
          */
         public static String HAS_CHILDREN = "hasChildren";
         /**
-         * This int column represents how often the folder should be synced.
+         * This int column represents how often the folder should be synchronized with the server.
          */
         public static String SYNC_FREQUENCY = "syncFrequency";
         /**
@@ -222,7 +222,7 @@
 
         public static String TOTAL_COUNT = "totalCount";
 
-        public FolderColumns() {};
+        public FolderColumns() {}
     }
 
     // We define a "folder" as anything that contains a list of conversations.