updated syntax highlighting support for perl and objective c in code_block and include_code plugins

plugins/include_code.rb

@@ -50,11 +50,13 @@ module Jekyll
 
       Dir.chdir(code_path) do
         code = file.read
-        file_type = file.extname
+        @filetype = file.extname
+        @filetype = 'objc' if @filetype == 'm'
+        @filetype = 'perl' if @filetype == 'pl'
         title = @title ? "#{@title} (#{file.basename})" : file.basename
         url = "#{context.registers[:site].config['url']}/#{code_dir}/#{@file}"
         source = "<div><figure role=code><figcaption><span>#{title}</span> <a href='#{url}'>download</a></figcaption>\n"
-        source += "{% highlight #{file_type} %}\n" + code + "\n{% endhighlight %}</figure></div>"
+        source += "{% highlight #{@filetype} %}\n" + code + "\n{% endhighlight %}</figure></div>"
         partial = Liquid::Template.parse(source)
         context.stack do
           partial.render(context)