use code generation to remove some duplication
peel and use aligned loads for sqrt
use macros instead of dummy functions to avoid implicit declarations
add aligned data generator and use it in tests
fix IS_ALIGNED and add assert to check output alignment
vectorize sqrt ufunc with SSE2

improves performance by 2/4 for float/double if the data is located
in the largest cpu cache which is quite often the case.
Merge branch 'sse2-sqrt' into simd-experiments

Conflicts:
	numpy/core/setup_common.py
	numpy/core/src/umath/loops.c.src
	numpy/testing/utils.py
use sse header macros for einsum sse activation
Merge branch 'sse2-sqrt' into simd-experiments