simd_array: implement setZero

refs #613

Signed-off-by: Matthias Kretz <kretz@kde.org>
make simd_cast a more generic replacement for StaticCastHelper

For Scalar and SSE: simd_cast now directly implements the conversions.
This is fully tested for 1 vector to 1 vector casts.
While at it I noticed that some casts as I copied from StaticCastHelper
were still not 100% correct.

refs #598

Signed-off-by: Matthias Kretz <kretz@kde.org>
simd_cast tests: test 4/2->1 and 1->2/4

Signed-off-by: Matthias Kretz <kretz@kde.org>
cmake: install traits headers

Signed-off-by: Matthias Kretz <kretz@kde.org>
clang-format should keep small functions on a single line

Signed-off-by: Matthias Kretz <kretz@kde.org>
use correct include path

it's "../common/" not just "common/"

Signed-off-by: Matthias Kretz <kretz@kde.org>
drop workaround for missing rvalue reference support

ICC now wants to support all of C++11, so let's drop these hacks

Signed-off-by: Matthias Kretz <kretz@kde.org>