Handle case where there is no snprintf()
libmysql.vcproj, mysqlclient.vcproj:
  Added __WIN__ symbol, needed when compiling dbug.c
dbug.vcproj:
  Changed __WIN32__ to __WIN__
dbug.c:
  Added Windows specific code to handle TIMESTAMP_ON log line format
make_win_src_distribution.sh:
  Copy plugin directory recursively
dbug.vcproj:
  Define __WIN__ for all targets