make --with-gcc-toolchain optional.
make --with-gcc-toolchain optional.

The correct value will be extracted automatically from the --prefix
option as printed by the --with-cc specified gcc compiler.
Also add a check in case there are more than 10 include paths as in that
case the code in TCling.cxx and rootcling.cxx need to be extended.

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