Functional callbacks on all Cog platforms

There's a simple example Alien class>>exampleCqsort that shows how to use the system and tests the implementation using the C library's sort quick sort implementation that takes a function pointer as an argument to use for comparing pairs of elements.  This is mapped onto a Smalltalk block by Alien's callback implementation.  The example sorts 100 random double-precision floats using qsort and a callback into Smalltalk.