* Adjust AO_..._H macros in public headers.
* Define AO macros for libatomic_ops version identification.
* Eliminate compiler warnings in various functions and macros.
+* Generalize AO_compare_and_swap primitives via AO_fetch_compare_and_swap.
* Improve Makefile for MS VC++; pass '-W3' option to MS compiler.
* Merge all Makefile.am files in src tree.
* Minor code refactoring of atomic_ops.c, generic_pthread.h.