Prune 20 obsolete ports

FreeBSD Ports maintainers have already deleted the following:
  devel/hs-hdoc
  devel/hs-idoc
  devel/llvm
  devel/py-pmock
  devel/qt4-declarative
  devel/qt4-qtestlib
  mail/p5-Mail-SPF-Query
  misc/bibletime-devel
  net-im/xfce4-messenger-plugin
  net-mgmt/unifi
  textproc/qt4-clucene
  textproc/referrercop
  www/codeigniter17
  www/mawstats
  www/mod_lisp2
  www/notftp
  www/qt4-webkit
  x11-fonts/etlfonts
  x11-toolkits/hs-frantk
  x11/qt4-opengl