Fix the example code in thrust::equal's documentation.

Fixes #359
Merge pull request #375 from jaredhoberock/trivial-fixes

Fix the example code in thrust::equal's documentation.
Actually launch the test kernel in this unit test.
Avoid recursion in sequential merge sort in CUDA threads.
Correct the threshold check in recursive_merge_sort to be <= rather than <
Correct the calculation of values_first2 in merge_adjacent_partitions_by_key.
Fix examples in is_partitioned examples.
Merge branch 'master' of github.com:thrust/thrust
Merge pull request #378 from jaredhoberock/iterative-sort

Iterative sort
Merge branch 'master' of github.com:jaredhoberock/thrust into device