Add Nathan's weld_vertices example
Add Nathan's weld_vertices example

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