Update to 0.0.12:

Render B<NULL> as .Dv NULL.
Correctly check the number of arguments.
Show the usage() message if there are too many arguments.
Mention the optional "file" argument in the usage() message.
Updated textproc/pod2mdoc to 0.0.12
Don't add -lfl on Linux either, causes issues.
Update to 2.84:

  * Fix peer communication vulnerability (no known exploits) reported
  by Ben Hawkes
Updated net/transmission to 2.84