Remove expired ports:
2018-12-19 net/ntop: Broken for more than 6 months
2018-12-19 textproc/ots: Broken for more than 6 months
2018-12-20 x11/xdialog: Uses obsolete glib12
2018-12-20 net/netdude: Uses obsolete glib12
2018-12-20 japanese/jmode-skk: Uses obsolete glib12
2018-12-20 print/gsview: Uses obsolete glib12
2018-12-20 x11/dgs: Uses obsolete glib12
2018-12-20 japanese/jmode: Uses obsolete glib12
2018-12-20 multimedia/xmms: Uses obsolete glib12