[fix] corrected mistakes introduced in the 4 previous blind commits
[evol] added gettext support using user prefered langage
[evol] separate signed mail processing from commands extracting, and improved order
[evol] new Mail facility create_simple_reject_reply(msg)
[evol] add missing licensing terms
[evol] check content-type protocol parameter when validating pgp mail content, and renamed tmail_extra library into tmail_gpg (as it is dedicated to gpg mails only)
[evol] replay protection #2 (should be done), and moved 'run' directory in the new workdir (temporary code until real path configuration)
[evol] check if signature timestamp is not too old or reject it (first part of the replay protection)
[evol] moved signed/encrypted mail creation from original mail to TMail class, and removed mail object duplication in the process (references to inners objects caused original mail to be altered, copying original headers instead)
[evol] set the 'micalg' parameter in signed mails
[evol] sign outgoing mails, and lot's of fixes and code improvement in mail handling (related to signing, crypting, and preparing/chaining the two)
[evol] handle incoming encrypted messages
[evol] activate outgoing mails
[evol] ensure DEB_RAILS_PATH is not set twice (but activeldap should do the same)
[evol] send reply for properly signed message with bad content + ensure setting custom headers in all cases
[evol] ensure sent mail is correctly formated (using Rails ActionMailer utility methods)
[evol] finished work on crypting mail response
[evol] preliminary work on crypting mail response
[evol] new DNS class to manage zone files (only read zone file at the moment) + generate proper mail reply
[evol] create basic mail reply and send it using SMTP
[evol] reorganized dependencies
[evol] moved the mail processing into a new class returning proper orders