Allow aggressive inlining of MD5 buffer updates (particularly for
fixed-size updates).
Make UTF-8 conversion a little faster.
This was SVN commit r7581.
also rename wchar -> utf8 to avoid conflict with <wchar.h> (requires
rebuild of workspace)
(unfortunately copying history fails to "502 bad gateway"; had to delete
old + add new independently)
This was SVN commit r7340.