EIT: improve documentation for i_extension
EIT: improve documentation for i_extension

paraeco/libdvbpsi,garbear/libdvbpsi,mwgoldsmith/dvbpsi,hiroshiyui/libdvbpsi,mkrufky/libdvbpsi,UIKit0/libdvbpsi,UIKit0/libdvbpsi,hiroshiyui/libdvbpsi,mkrufky/libdvbpsi,krieger-od/libdvbpsi,hiroshiyui/libdvbpsi,vlc-mirror/libdvbpsi,mwgoldsmith/dvbpsi,garbear/libdvbpsi,mkrufky/libdvbpsi,avble/libdvbpsi,vlc-mirror/libdvbpsi,mwgoldsmith/dvbpsi,UIKit0/libdvbpsi,avble/libdvbpsi,avble/libdvbpsi,mwgoldsmith/dvbpsi,vlc-mirror/libdvbpsi,paraeco/libdvbpsi,garbear/libdvbpsi,paraeco/libdvbpsi,krieger-od/libdvbpsi,krieger-od/libdvbpsi,paraeco/libdvbpsi