Better support for class that used to have version==0.
Better support for class that used to have version==0.

In the case where the class used to have a version number set to 0
(i.e. don't stream any of its content) but the version number is
now set to greater than zero, we need to avoid reading a non-existant
checksum from the buffer.

krafczyk/root,nilqed/root,dfunke/root,buuck/root,jrtomps/root,omazapa/root,0x0all/ROOT,mkret2/root,esakellari/root,buuck/root,jrtomps/root,olifre/root,Y--/root,abhinavmoudgil95/root,mattkretz/root,gbitzes/root,agarciamontoro/root,abhinavmoudgil95/root,omazapa/root-old,mattkretz/root,mkret2/root,sirinath/root,davidlt/root,gganis/root,davidlt/root,zzxuanyuan/root-compressor-dummy,buuck/root,thomaskeck/root,smarinac/root,krafczyk/root,sirinath/root,krafczyk/root,gbitzes/root,olifre/root,veprbl/root,sawenzel/root,esakellari/my_root_for_test,omazapa/root-old,lgiommi/root,mkret2/root,esakellari/my_root_for_test,satyarth934/root,sbinet/cxx-root,gbitzes/root,lgiommi/root,krafczyk/root,Duraznos/root,sbinet/cxx-root,sawenzel/root,CristinaCristescu/root,nilqed/root,smarinac/root,mattkretz/root,0x0all/ROOT,perovic/root,karies/root,pspe/root,davidlt/root,gganis/root,omazapa/root-old,davidlt/root,karies/root,beniz/root,sbinet/cxx-root,karies/root,gganis/root,satyarth934/root,gbitzes/root,sirinath/root,evgeny-boger/root,davidlt/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root,dfunke/root,sawenzel/root,abhinavmoudgil95/root,Duraznos/root,Y--/root,karies/root,zzxuanyuan/root,mhuwiler/rootauto,sawenzel/root,sawenzel/root,Duraznos/root,krafczyk/root,jrtomps/root,satyarth934/root,dfunke/root,bbockelm/root,lgiommi/root,sirinath/root,mattkretz/root,BerserkerTroll/root,esakellari/root,nilqed/root,mkret2/root,thomaskeck/root,veprbl/root,buuck/root,olifre/root,BerserkerTroll/root,mhuwiler/rootauto,arch1tect0r/root,esakellari/root,nilqed/root,dfunke/root,perovic/root,olifre/root,esakellari/my_root_for_test,CristinaCristescu/root,0x0all/ROOT,agarciamontoro/root,CristinaCristescu/root,perovic/root,smarinac/root,lgiommi/root,vukasinmilosevic/root,smarinac/root,sawenzel/root,gganis/root,esakellari/my_root_for_test,Duraznos/root,esakellari/my_root_for_test,sawenzel/root,esakellari/my_root_for_test,veprbl/root,esakellari/root,mattkretz/root,CristinaCristescu/root,zzxuanyuan/root-compressor-dummy,beniz/root,smarinac/root,zzxuanyuan/root-compressor-dummy,buuck/root,karies/root,buuck/root,omazapa/root,vukasinmilosevic/root,gganis/root,evgeny-boger/root,sawenzel/root,thomaskeck/root,bbockelm/root,agarciamontoro/root,esakellari/root,lgiommi/root,karies/root,omazapa/root,sbinet/cxx-root,beniz/root,perovic/root,abhinavmoudgil95/root,beniz/root,simonpf/root,olifre/root,smarinac/root,root-mirror/root,gbitzes/root,root-mirror/root,dfunke/root,mhuwiler/rootauto,bbockelm/root,BerserkerTroll/root,BerserkerTroll/root,Duraznos/root,bbockelm/root,omazapa/root-old,CristinaCristescu/root,CristinaCristescu/root,CristinaCristescu/root,beniz/root,esakellari/root,esakellari/root,BerserkerTroll/root,nilqed/root,sbinet/cxx-root,davidlt/root,sawenzel/root,omazapa/root-old,Y--/root,georgtroska/root,Y--/root,Duraznos/root,mkret2/root,beniz/root,jrtomps/root,satyarth934/root,omazapa/root-old,sbinet/cxx-root,vukasinmilosevic/root,zzxuanyuan/root-compressor-dummy,CristinaCristescu/root,bbockelm/root,esakellari/root,vukasinmilosevic/root,0x0all/ROOT,krafczyk/root,zzxuanyuan/root-compressor-dummy,sawenzel/root,veprbl/root,gbitzes/root,omazapa/root,arch1tect0r/root,buuck/root,Duraznos/root,jrtomps/root,BerserkerTroll/root,root-mirror/root,nilqed/root,pspe/root,sirinath/root,jrtomps/root,sirinath/root,vukasinmilosevic/root,sbinet/cxx-root,Duraznos/root,root-mirror/root,georgtroska/root,root-mirror/root,lgiommi/root,veprbl/root,karies/root,mattkretz/root,davidlt/root,satyarth934/root,bbockelm/root,georgtroska/root,mhuwiler/rootauto,evgeny-boger/root,veprbl/root,esakellari/my_root_for_test,omazapa/root,zzxuanyuan/root-compressor-dummy,Y--/root,esakellari/my_root_for_test,davidlt/root,zzxuanyuan/root,veprbl/root,gganis/root,beniz/root,nilqed/root,omazapa/root,veprbl/root,omazapa/root-old,olifre/root,perovic/root,krafczyk/root,omazapa/root-old,olifre/root,agarciamontoro/root,nilqed/root,arch1tect0r/root,pspe/root,vukasinmilosevic/root,sirinath/root,georgtroska/root,esakellari/root,jrtomps/root,nilqed/root,veprbl/root,Y--/root,arch1tect0r/root,beniz/root,thomaskeck/root,gganis/root,mattkretz/root,georgtroska/root,omazapa/root-old,satyarth934/root,georgtroska/root,smarinac/root,satyarth934/root,thomaskeck/root,simonpf/root,nilqed/root,perovic/root,zzxuanyuan/root,karies/root,lgiommi/root,mkret2/root,lgiommi/root,dfunke/root,simonpf/root,zzxuanyuan/root,perovic/root,pspe/root,agarciamontoro/root,jrtomps/root,sbinet/cxx-root,Y--/root,veprbl/root,beniz/root,dfunke/root,gganis/root,mkret2/root,bbockelm/root,arch1tect0r/root,buuck/root,olifre/root,abhinavmoudgil95/root,gganis/root,sirinath/root,arch1tect0r/root,thomaskeck/root,Y--/root,krafczyk/root,mhuwiler/rootauto,omazapa/root,CristinaCristescu/root,abhinavmoudgil95/root,0x0all/ROOT,Y--/root,davidlt/root,BerserkerTroll/root,pspe/root,bbockelm/root,gbitzes/root,davidlt/root,jrtomps/root,agarciamontoro/root,arch1tect0r/root,evgeny-boger/root,mhuwiler/rootauto,Duraznos/root,zzxuanyuan/root-compressor-dummy,karies/root,arch1tect0r/root,agarciamontoro/root,satyarth934/root,simonpf/root,mkret2/root,beniz/root,mkret2/root,evgeny-boger/root,buuck/root,mkret2/root,smarinac/root,root-mirror/root,vukasinmilosevic/root,dfunke/root,bbockelm/root,lgiommi/root,smarinac/root,simonpf/root,0x0all/ROOT,gbitzes/root,abhinavmoudgil95/root,pspe/root,BerserkerTroll/root,lgiommi/root,Y--/root,vukasinmilosevic/root,Duraznos/root,georgtroska/root,buuck/root,omazapa/root-old,simonpf/root,thomaskeck/root,Duraznos/root,olifre/root,agarciamontoro/root,dfunke/root,mhuwiler/rootauto,BerserkerTroll/root,gbitzes/root,mhuwiler/rootauto,simonpf/root,abhinavmoudgil95/root,omazapa/root,vukasinmilosevic/root,zzxuanyuan/root,satyarth934/root,karies/root,BerserkerTroll/root,krafczyk/root,zzxuanyuan/root,perovic/root,bbockelm/root,omazapa/root,evgeny-boger/root,pspe/root,BerserkerTroll/root,vukasinmilosevic/root,arch1tect0r/root,krafczyk/root,gganis/root,pspe/root,bbockelm/root,dfunke/root,krafczyk/root,simonpf/root,zzxuanyuan/root,georgtroska/root,CristinaCristescu/root,agarciamontoro/root,satyarth934/root,agarciamontoro/root,simonpf/root,root-mirror/root,gbitzes/root,arch1tect0r/root,omazapa/root,evgeny-boger/root,omazapa/root-old,abhinavmoudgil95/root,thomaskeck/root,gganis/root,jrtomps/root,jrtomps/root,evgeny-boger/root,pspe/root,georgtroska/root,esakellari/root,simonpf/root,olifre/root,vukasinmilosevic/root,evgeny-boger/root,thomaskeck/root,pspe/root,omazapa/root,georgtroska/root,arch1tect0r/root,root-mirror/root,perovic/root,sbinet/cxx-root,mattkretz/root,sbinet/cxx-root,esakellari/my_root_for_test,root-mirror/root,mattkretz/root,smarinac/root,mhuwiler/rootauto,pspe/root,dfunke/root,abhinavmoudgil95/root,zzxuanyuan/root-compressor-dummy,georgtroska/root,root-mirror/root,esakellari/root,zzxuanyuan/root,davidlt/root,Y--/root,beniz/root,CristinaCristescu/root,zzxuanyuan/root-compressor-dummy,simonpf/root,lgiommi/root,buuck/root,zzxuanyuan/root,olifre/root,satyarth934/root,zzxuanyuan/root,esakellari/my_root_for_test,perovic/root,mkret2/root,root-mirror/root,sirinath/root,evgeny-boger/root,mhuwiler/rootauto,karies/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root,abhinavmoudgil95/root,sawenzel/root,agarciamontoro/root,mattkretz/root,veprbl/root,evgeny-boger/root,mattkretz/root,thomaskeck/root,nilqed/root,perovic/root,sirinath/root,sbinet/cxx-root,sirinath/root,0x0all/ROOT,0x0all/ROOT,gbitzes/root,mhuwiler/rootauto,0x0all/ROOT