Ensure vector3df and all classes containing a vector3df are passed by reference instead of per value. Thanks @Danyal Zia for the patch (#280).
This is breaking the IAttributes interface - so anyone who derived from that will have to update his implementation. More changes in that interface probably coming later today.
The idea behind the patch is preparing the engine for SSE support.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4725 dfc29bdd-3216-0410-991c-e03cc46cb475