PERF: stop messing with strings that come back from I18n.t

allows better caching

lib/email/message_builder.rb

@@ -69,7 +69,7 @@ module Email
 
     def body
       body = @opts[:body]
-      body = I18n.t("#{@opts[:template]}.text_body_template", template_args) if @opts[:template]
+      body = I18n.t("#{@opts[:template]}.text_body_template", template_args).dup if @opts[:template]
 
       if @opts[:add_unsubscribe_link]
         body << "\n"

lib/freedom_patches/translate_accelerator.rb

@@ -16,10 +16,10 @@ module I18n
       k = [args,config.locale,config.backend.object_id]
       t  = @cache.fetch(k){found=false}
       unless found
-        t = @cache[k] = translate_no_cache(*args)
+        t = @cache[k] = translate_no_cache(*args).freeze
       end
 
-      t.dup
+      t
     end
 
     alias_method :t, :translate

lib/pretty_text.rb

@@ -12,6 +12,7 @@ module PrettyText
       if opts
         # TODO: server localisation has no parity with client
         # should be fixed
+        str = str.dup
         opts.each do |k,v|
           str.gsub!("{{#{k}}}", v)
         end

lib/site_content_class_methods.rb

@@ -25,9 +25,9 @@ module SiteContentClassMethods
     result = ""
     if site_content.blank?
       ct = find_content_type(content_type)
-      result = ct.default_content if ct.present?
+      result = ct.default_content.dup if ct.present?
     else
-      result = site_content.content
+      result = site_content.content.dup
     end
 
     result.gsub!(/\%\{[^}]+\}/) do |m|