cstdint -> stdint.h; cstdint doesn't always exist on a mac (sometimes it's tr1/cstdint)
{} initializers to ()
constexpr -> const
no particular need for postfix return type
static_assert -> SIMDPP_STATIC_ASSERT
some returns made explicit
if this is going to live in a branch, no point to the #if
math_shift returns
replace std::array and auto in make_shuffle_bytes_mask
all returns explicit now?
compare.h doesn't need postfix return types either
unused variables in memory_{load,store}.h
remove brace initializers from memory_{load,store}.h