Log Message:
Changes 1.2.4:
- Changed return code in case of authentication error from EX_DATAERR
  to EX_NOPERM
- Changed return code in case of missing/invalid configuration file or
  nonexistent account from EX_NOINPUT/EX_DATAERR to EX_CONFIG
- Test return value of localtime(3) in msmtp_log()
- Windows specific code in net.c: moved translation of error code from
  WSAStartup() from net_lib_init() to wsa_strerror()
- OpenSSL specific code in tls.c: minor cleanup in openssl_io_error()
- Always keep control of the format string in calls to merror(). (There
  were four cases where the result of strerror() was passed as the format
  string in smtp.c.)
- Clarified usage instructions of merror() in merror.h
- Check at initialization time whether support for a manually requested
  authentication mechanism is compiled, *before* establishing a network
  connection.
  This required a change from smtp_auth_caps() to the (equally trivial)
  smtp_authmech_is_supported() function.
  Made the output of both "not compiled in" messages (TLS and auth mech)
  consistent.
  The return code for these error conditions is EX_UNAVAILABLE now.
- Make the output of -h/--help and -v/--version consistent with the GNU
  utilities by including copyright and no-warranty notice (version) and
  a short description and the bug report address (--help).
- Add missing declarations of optarg and optind to msmtp.c, needed for
  getopt() handling. No compiler complained so far, though.
- Fixed stupid error in smtp.c that prevented the detection of output
  errors when sending the RCPT TO command (highly unlikely to occur).
- Cosmetic change in -v/--version output that avoids lines longer than
  80 characters
- Fixed some man page typos
- Fixed typos in conffile.c error message
- Fixed typo in tls.c error message (OpenSSL code only)
- Changed error messages: "bla [blub]" -> "bla: blub"
- Improved some TLS error messages
- Corrected short description in man page, README and code comments
- Updated README.dos