add unfavorite option in context menu

res/menu/file_actions_menu.xml

@@ -30,7 +30,8 @@
     <item 	android:id="@+id/action_move"					android:title="@string/actionbar_move"				android:icon="@android:drawable/ic_menu_set_as"					android:orderInCategory="1" />
     <item 	android:id="@+id/action_remove_file"			android:title="@string/common_remove"				android:icon="@android:drawable/ic_menu_delete"					android:orderInCategory="1" />
     <item 	android:id="@+id/action_send_file"				android:title="@string/actionbar_send_file"			android:icon="@android:drawable/ic_menu_set_as"					android:orderInCategory="1" />
-    <item 	android:id="@+id/action_favourite_file"			android:title="@string/fd_keep_in_sync"		    	android:icon="@android:drawable/ic_menu_set_as"					android:orderInCategory="1" />
+    <item 	android:id="@+id/action_favorite_file"			android:title="@string/fd_keep_in_sync"		    	android:icon="@android:drawable/ic_menu_set_as"					android:orderInCategory="1" />
+    <item 	android:id="@+id/action_unfavorite_file"		android:title="@string/unfavorite"		    	    android:icon="@android:drawable/ic_menu_set_as"					android:orderInCategory="1" />
     <item 	android:id="@+id/action_see_details"			android:title="@string/actionbar_see_details"		android:icon="@android:drawable/ic_menu_info_details"			android:orderInCategory="1" />
 
 </menu>

res/values/strings.xml

@@ -201,6 +201,7 @@
     <string name="auth_account_does_not_exist">Account does not exist in the device yet</string>
     
     <string name="fd_keep_in_sync">Favorite</string>
+    <string name="unfavorite">Unfavorite</string>
     <string name="common_rename">Rename</string>
     <string name="common_remove">Remove</string>
     <string name="confirmation_remove_alert">"Do you really want to remove %1$s?"</string>