Re: [tz] Asia/Shanghai timezone history and other information

Thanks for that detailed info about Shanghai and environments. I installed into the development repository the attached proposed patch, which adds a DST period in Shanghai from April 13 00:00 to October 1 00:00, plus adds your commentary about the confusing situation in the area at the time. This patch also adds confirming info from the English-language Returns of Trade and Trade Reports, 1919.