src/descriptor.h: Add more detail in doxygen comments.
src/descriptor.h: Add more detail in doxygen comments.

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