adds command chains back to SConstruct
adds command chains back to SConstruct

tempbottle/cppitertools,jkhoogland/cppitertools,tempbottle/cppitertools,ryanhaining/cppitertools,tempbottle/cppitertools,ryanhaining/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools,jkhoogland/cppitertools