partition.h (__parallel_partition): Correctly initialize chunk size.

2009-11-19  Johannes Singler  <singler@kit.edu>

        * include/parallel/partition.h (__parallel_partition): Correctly
        initialize chunk size.
        (__parallel_nth_element): Respect nth_element_minimal_n.  Use
        sequential nth_element as base case, instead of sequential sort.

From-SVN: r154333