merge revision(s) 43177,43191: [Backport #8991]

	* lib/time.rb (Time.strptime): Use :offset.
	  Patch by Felipe Contreras.  [ruby-core:57694]

	* lib/time.rb (Time.strptime): Time.strptime('0', '%s') returns local
	  time Time object as Ruby 2.0 and before.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@43221 b2dd03c8-39d4-4d8f-98ff-823fe69b080e