Rigs of Rods

Add ZeroedMemoryAllocator class to automatically initialize memory of objects. This removes the need for explicit initialization of memory of data structures, which either get forgotten or gradually increase code size.

The attached patch includes the code as used in OpenTTD, with minor tweaks for compilation in RoR's codebase; NORETURN is removed, byte has been changed to unsigned char, and Ogre's LogManager is used.

A brief test of this patch does work for me, however as it fundamentally changes the allocation method of the class it's used in, this patch will require thorough testing. It may also be worth using the allocator class on other classes within RoR.