minor formatting in mandelbrot_nt2, added more benchmarks
add more benchmarks to mandelbrot scalar
made for loops in mandelbrot_simd consistent with the other simd demos, add more benchmarks
added more benchamrks to rgb2yuv scalar, nt2, simd
added more benchmarks to saxpy scalar, nt2, simd and mkl
sped up nt2 implementation of sdot by using operator * and global_sum. added more benchmarks sdot_nt2
added more benchmarks to sdot scalar and simd
added more benchmarks to sigma_delta scalar and nt2
made for loop in sigma_delta simd the same as the other simd demos. added more benchmarks.