feat(messages): render markdown in message body

uses redcarpet gem to render markdown to html. Also a html email template
is added.

plugins/messages/app/models/message.rb

@@ -137,4 +137,4 @@ class Message < ApplicationRecord
   def create_salt
     self.salt = [Array.new(6) { rand(256).chr }.join].pack("m").chomp
   end
-end
+end

plugins/messages/app/views/messages/show.haml

@@ -33,7 +33,7 @@
         - if @message.can_toggle_private?(current_user)
           = link_to t('.change_visibility'), toggle_private_message_path(@message), method: :post, class: 'btn btn-mini'
   %hr/
-  %p= simple_format(h(@message.body))
+  = markdown(@message.body)
   %hr/
   %p
     = link_to t('.reply'), new_message_path(:message => {:reply_to => @message.id}), class: 'btn'

plugins/messages/app/views/messages/thread.haml

@@ -9,7 +9,7 @@
     .panel-heading
       %b= h(message.sender_name)
       = format_time(message.created_at)
-    .panel-body= simple_format(h(message.body))
+    .panel-body= markdown(message.body)
 
 %p
   = link_to t('.reply'), new_message_path(:message => {:reply_to => thread_message.id}), class: 'btn'

plugins/messages/app/views/messages_mailer/foodsoft_message.html.haml

@@ -0,0 +1,6 @@
+= markdown(@message.body)
+%hr/
+%pre
+  - if @message.group
+    = raw t '.footer_group', group: @message.group.name
+  = raw t '.footer', reply_url: new_message_url('message[reply_to]' => @message.id), msg_url: message_url(@message), profile_url: my_profile_url