Allow disabling plugins for faster preview

_plugins/sitemap.rb

@@ -14,11 +14,23 @@ module Jekyll
 
   class SitemapGenerator < Generator
     def generate(site)
+      #Do nothing if plugin is disabled
+      if !ENV['ENABLED_PLUGINS'].nil? and ENV['ENABLED_PLUGINS'].index('sitemap').nil?
+        print 'Sitemap disabled' + "\n"
+        return
+      end
       #Load translations
       locs = {}
+      enabled = ENV['ENABLED_LANGS'];
+      enabled = enabled.split(' ') if !enabled.nil?
       Dir.foreach('_translations') do |file|
         next if file == '.' or file == '..'
         lang=file.split('.')[0]
+        #Ignore lang if disabled
+        if lang != 'en' and !enabled.nil? and !enabled.include?(lang)
+          print 'Lang ' + lang + ' disabled' + "\n"
+          next
+        end
         locs[lang] = YAML.load_file('_translations/'+file)[lang]
       end
       #Create destination directory if does not exists