[tools] Not twine generates only useful files.

tools/twine/lib/twine/formatters/abstract.rb

@@ -153,7 +153,7 @@ module Twine
 
         file_name = @options[:file_name] || default_file_name
         Dir.foreach(path) do |item|
-          if File.directory?(item)
+          if File.directory?(path + File::SEPARATOR + item)
             lang = determine_language_given_path(item)
             if lang
               write_file(File.join(path, item, file_name), lang)

tools/twine/lib/twine/formatters/android.rb

@@ -40,7 +40,7 @@ module Twine
               lang = match[1]
               lang = LANG_CODES.fetch(lang, lang)
               lang.sub!('-r', '-')
-              return lang
+              return lang =~ /land|port|v\d+|sw\d+/ ? nil : lang
             end
           end
         end