Prune 13 obsolete ports

FreeBSD Ports maintainers have already deleted the following:
  archivers/xz
  databases/postgis
  devel/lua-filename
  devel/mico
  emulators/seabios-devel
  games/deng
  lang/python26
  misc/sword17
  net-mgmt/nagios-devel
  sysutils/lavaps
  textproc/redland-bindings-python
  www/mod_authnz_external
  www/suphp
Failure: ports-mgmt/pkg v1.2.5
Failure: ports-mgmt/pkg-devel v1.2.5