parallel_scan example with double data is not deterministic

[jnorwood]

I modified fig_2_14 example to test if operations on double data are deterministic, since I didn't find anything similar to parallel_deterministic_reduce.

The result of the test indicates repeat of a parallel_scan example with operations on double data results in different return values from the parallel_scan example doing sums.

I'll attach my example.

fig_2_14_double.txt