Add handling for message reply via email

If the reply_email_domain configuration is set the messages plugin will
use unique Reply-To addresses for every email. They contain enough
information to reconstruct the message context and a hash to avoid
user forgery and spam.
A mail transfer agent must be configured to call the new rake task
foodsoft:parse_reply_email for incoming mails. The rake task requires
the receipt of the mail in the RECIPIENT variable and the raw message
via standard input. An example invocation would look like:
rake foodsoft:parse_reply_email RECIPIENT=f.1.1.HASH < test.eml

Gemfile.lock

@@ -15,7 +15,9 @@ PATH
   remote: plugins/messages
   specs:
     foodsoft_messages (0.0.1)
+      base32
       deface (~> 1.0.0)
+      mail
       rails
 
 PATH
@@ -71,6 +73,7 @@ GEM
     addressable (2.4.0)
     arel (6.0.3)
     attribute_normalizer (1.2.0)
+    base32 (0.3.2)
     better_errors (2.1.1)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
@@ -534,3 +537,6 @@ DEPENDENCIES
   uglifier (>= 1.0.3)
   web-console (~> 2.0)
   whenever
+
+BUNDLED WITH
+   1.10.6