Hide __MACOSX folders in file tree in speedgraders (#1342)

* Consider the case of folder being mac_bs_file.

* Update comment.

lib/archive.rb

@@ -84,13 +84,25 @@ def self.sanitize_directories(files)
       # exist. If it does not, create and add them
       if(!file[:directory])
         paths = file[:pathname].split("/")
+        mac_bs_file = false
+        for path in paths do
+          # note that __MACOSX is actually a folder
+          # need to check whether the path includes that
+          # for the completeness of cleaned_files
+          # mac_bs_file folder paths will still be added
+          if path.include?("__MACOSX") || path.include?(".DS_Store") ||
+             path.include?(".metadata")
+             mac_bs_file = true
+             break
+          end
+        end
         for i in 1..(paths.size - 1) do
           new_path = paths[0,paths.size-i].join("/") + "/"
           if(!file_path_set.include?(new_path))
             cleaned_files.append({
               :pathname=>new_path,
               :header_position=>starting_header,
-              :mac_bs_file=>false,
+              :mac_bs_file=>mac_bs_file,
               :directory=>true
             })
             starting_header = starting_header - 1