583023

The DNS plugin is getting old, tired and already looking forward to his
pension in the Carribean. It will be replaced soon by a younger, faster,
safer, shorter (in terms of code) and more maintainable version.
Until that happens, here's some medicine for the old guy:
- proper output definitions: the DNS plugin was created before we
  had the has_output attribute in place
- --all: this is related to the output definitions as
  Command.get_options() adds the --all and --raw options automatically
  if has_output contains entries
- dns-add-rr overwritting: missing .lower() caused records to be
  overwritten everytime a new one was added from the CLI

We were being left with orphan services if the host entry was not removed
using the FQDN.

I also changed the default value of the print_all argument in
textui.print_entry from False to True. It think it makes more sense this
way, because:

1) if order is None, it will still print something
2) if order is not None, it will print what's in order first and then the
   rest
3) commands that care about the print_all argument have to set it in any
   case, those that don't care usually want to print everything