support per-thread default stream
support per-thread default stream

jaredhoberock/thrust,thrust/thrust,andrewcorrigan/thrust-multi-permutation-iterator,jaredhoberock/thrust,thrust/thrust,jaredhoberock/thrust,thrust/thrust,thrust/thrust,jaredhoberock/thrust,jaredhoberock/thrust,thrust/thrust,andrewcorrigan/thrust-multi-permutation-iterator,andrewcorrigan/thrust-multi-permutation-iterator