Add the DragonFly Mail Agent dma(8) to the base.

Add the DragonFly Mail Agent dma(8) to the base.

dma is a small Mail Transport Agent (MTA), designed for home and office
use.  It accepts mails from locally installed Mail User Agents (MUA) and
delivers the mails either locally or to a remote destination.  Remote
delivery includes several features like TLS/SSL support and SMTP authen-
tication (AUTH LOGIN only).

dma is not intended as a replacement for real, big MTAs like sendmail(8)
or postfix(8).  Consequently, dma does not listen on port 25 for incoming
connections.

Current list of features:
- Local mail delivery with alias-support
- Remote mail delivery either direct or via a smarthost
- TLS/SSL and STARTTLS support for encrypted connections
- virtualusers (address rewriting) support
- SMTP authentication (currently only plain SMTP login)
- Sendmail compatible command line options
- IPv6 support

Code-collaboration-with: codecode@
Man-page-collaboration-with: swildner@
Approved-by: dillon@