dr_45.h: document some defines.
dr_45.h: document some defines.

mwgoldsmith/dvbpsi,vlc-mirror/libdvbpsi,garbear/libdvbpsi,garbear/libdvbpsi,vlc-mirror/libdvbpsi,paraeco/libdvbpsi,paraeco/libdvbpsi,UIKit0/libdvbpsi,UIKit0/libdvbpsi,paraeco/libdvbpsi,mwgoldsmith/dvbpsi,mkrufky/libdvbpsi,mwgoldsmith/dvbpsi,mkrufky/libdvbpsi,mwgoldsmith/dvbpsi,vlc-mirror/libdvbpsi,paraeco/libdvbpsi,mkrufky/libdvbpsi,garbear/libdvbpsi,UIKit0/libdvbpsi