Version 4.12, October 5, 2016

This version is a relatively minor update mainly consisting of bug fixes
and Microsoft/GNU/Clang compatibility improvements.  It does include
the following features and notable changes:

1. A new mechanism to handle builtin functions.  This was made necessary by the
   thousands of builtin functions now present in GNU and/or clang.  The new
   mechanism is also used to handle Microsoft builtins.  See the 9/16/16
   Changes entry for more details.

2. C11 atomic types are now supported.  See the 7/6/16 Changes entry for
   more information.

3. A few more C++17 features have been implemented:
     - Nested namespace definitions (N4230)
     - Terse static_assert (N3928)
     - Relaxed range-based for loop (P0184R0)

4. The --ms_c++14 and --ms_c++latest command-line options have been provided to
   emulate the Microsoft std:c++14 and /std:c++latest options.  See the
   6/27/16 Changes entry for more information.

As usual, we have fixed bugs, added many minor features, and continued to
improve our various compatibility modes.  See the Changes_4.12 file for
full details (about 3,900 lines).
