I found these packages on the OpenWebif:

enigma2-plugin-extensions-subssupport (1.5.6-r0)
Collection of enigma2 subtitles plugins
enigma2-plugin-extensions-subssupport-dbg (1.5.6-r0)
Collection of enigma2 subtitles plugins - Debugging files
enigma2-plugin-extensions-subssupport-dev (1.5.6-r0)
Collection of enigma2 subtitles plugins - Development files