* win32/win32.c (gettimeofday): shouldn't use mktime(2) because it's
	  buggy about handling summer time.
	  reported by Yoshikawa <yoshixool AT gmail.com> at [ruby-dev:36071]
	* win32/win32.c (gettimeofday): calc tv_sec and tv_usec from system
	  time by myself. [ruby-dev:36084]
	* win32/win32.c (gettimeofday): tv_usec is usec, not msec.
	  [ruby-dev:36094]
	  of the Gregorian calendar.
	* win32/win32.c (filetime_to_timeval): new function, split from
	  gettimeofday().
	* win32/win32.c (gettimeofday): use above function.
	* win32/win32.c (filetime_to_unixtime): ditto. [ruby-dev:36135]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_7@21705 b2dd03c8-39d4-4d8f-98ff-823fe69b080e