added template default arguments for iterator_facade - Reference and Difference - to match boost::iterator_facade
added template default arguments for iterator_facade - Reference and Difference - to match boost::iterator_facade

sdalton1/thrust,jaredhoberock/thrust,egaburov/thrust,thrust/thrust,zeryx/thrust,thvasilo/thrust,arnabgho/thrust,jaredhoberock/thrust,thrust/thrust,xiongzhanblake/thrust,thvasilo/thrust,sarvex/thrust,xiongzhanblake/thrust_src,Ricardo666666/thrust,sdalton1/thrust,zhenglaizhang/thrust,mohamed-ali/thrust,GrimDerp/thrust,arnabgho/thrust,dachziegel/thrust,thrust/thrust,thvasilo/thrust,GrimDerp/thrust,marksantos/thrust,andrewcorrigan/thrust-multi-permutation-iterator,egaburov/thrust,mohamed-ali/thrust,thrust/thrust,sdalton1/thrust,xiongzhanblake/thrust,andrewcorrigan/thrust-multi-permutation-iterator,andrewcorrigan/thrust-multi-permutation-iterator,egaburov/thrust,xiongzhanblake/thrust_src,thrust/thrust,arnabgho/thrust,zhenglaizhang/thrust,dachziegel/thrust,marksantos/thrust,sarvex/thrust,Ricardo666666/thrust,xiongzhanblake/thrust_src,jaredhoberock/thrust,zeryx/thrust,xiongzhanblake/thrust,marksantos/thrust,GrimDerp/thrust,raygit/thrust,sarvex/thrust,raygit/thrust,zeryx/thrust,jaredhoberock/thrust,dachziegel/thrust,mohamed-ali/thrust,zhenglaizhang/thrust,jaredhoberock/thrust,raygit/thrust,Ricardo666666/thrust