Added a slab allocator

Added a slab allocator which replaces the use of memory pools or the plain AllocMem() operations, respectively. In order to activate the slab allocator, choose a slab size (e.g. 2048 bytes or 4096 bytes) and declare a global variable like this:

   ULONG __slab_max_size = 2048;

Memory allocations smaller than the slab size will be made from "slabs", i.e. large chunks of memory of the given size. Larger allocations will be managed separately.

library/debug.lib_rev.rev

@@ -1 +1 @@
-206
+207