Ticket 63 - segfault in thr_stack_create.
    
    Bug Description:  LFDS710_PAL_ASSERT would trigger a sefault to indicate a
    runtime issue in the lfds code. This was because we were allocating memory
    that was not aligned in a manner that was able to be used by atomic CPU
    instructions.
    
    Fix Description:  Add a ns_memalign function, and the os wrappers to allow
    aligned allocation of memory for the purposes of lfds to consume.
    
    https://fedorahosted.org/nunc-stans/ticket/63
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)