Adding "mail2Fax"-command
- this "mail2fax" contains a simple extension to send mails to the capisuite
  which sends the email-contene out as fax
- it works for Exim4, by setting up a dedicated subdomain handling the fax-
  feature (fax.example.com)
- the user-part of the emails are the fax-numers to send to (045214@fax.example.com)
- the "csfax_helper" handles plaintext-emails and multipart-emails (only the 1st
  attachment, which is no PGP-signature, will be faxed)
setting domain to "fax.example.com"
formatting:
- removing unused code
- changing log-message "subject field" to "subject header"
improve failure handling
- add testing for required binaries
- aleaning of code to handle "plain-text"-mails
Merge branch 'master' of https://github.com/SvenRoederer/capisuite
backmerge from upstream
Merge branch 'master' of https://github.com/SvenRoederer/capisuite