setup.py to fix RPATH problem.

Add an intermediate method to propagate the friendship access to nested classes as a workaround for old compilers (e.g. gcc 3.4)

Use Subprocess::Win32ErrorMessage() in command_line_interface_unittest to make the it OS locale independent.

Roll back revision 313.  A similar but far more exensive change was made in our internal branch, which will be integrated soon.

Improve coded_stream.h handling on MSVC.  Avoid a bogus runtime check and enable little-endian optimization.  Based on patch from Nathan McDaniel.