Fix inability to pass arguments to getlocal.

Before this patch you cannot pass additional arguments to ActiveSupport::TimeWithZone#getlocal
You can do this:
Time.now.getlocal(14400) # 2014-09-22 20:20:18 +0400
Now you can do this either (was throwing "wrong number of arguments (1 for 0)" before):
Time.current.getlocal(14400) 
Time.zone.now.getlocal(14400)