Apple contribution for OSX SSE and iOS NEON optimizations unit tests, thanks to Jordan Hubbard, Ian Ollmann and Hristo Hristov.

For OSX:
cd build
./premake_osx xcode4
for iOS:
cd build
./ios_build.sh
./ios_run.sh

Also integrated the branches/StackAllocation to make it easier to multi-thread collision detection in the near future. It avoids changing the btCollisionObject while performing collision detection.

As this is a large patch, some stuff might be temporarily broken, I'll keep an eye out on issues.

src/LinearMath/btGrahamScan2dConvexHull.h

@@ -70,7 +70,8 @@ inline void GrahamScanConvexHull2D(btAlignedObjectArray<GrahamVector2>& original
 	{
 		const btVector3& left = originalPoints[i];
 		const btVector3& right = originalPoints[0];
-		if (left.x() < right.x() || !(right.x() < left.x()) && left.y() < right.y())
+		if (left.x() < right.x() || 
+            (!(right.x() < left.x()) && left.y() < right.y()))
 		{
 			originalPoints.swap(0,i);
 		}