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.

Fix missing header issue -- INT_MAX is defined in limits.h.  I chose to use a different constant rather than add the #include.

Fix issues with Windows build:  Always use ASCII version of CreateProcess (even if UNICODE is defined) and move GetMessage macro work-around to common.h so that it covers extension_set.h as well.  Patch from Nick Carter.