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/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h

@@ -68,7 +68,7 @@ subject to the following restrictions:
 
   For usage and testing see the TerrainDemo.
  */
-class btHeightfieldTerrainShape : public btConcaveShape
+ATTRIBUTE_ALIGNED16(class) btHeightfieldTerrainShape : public btConcaveShape
 {
 protected:
 	btVector3	m_localAabbMin;
@@ -116,6 +116,9 @@ protected:
 	                PHY_ScalarType heightDataType, bool flipQuadEdges);
 
 public:
+	
+	BT_DECLARE_ALIGNED_ALLOCATOR();
+	
 	/// preferred constructor
 	/**
 	  This constructor supports a range of heightfield