[tz] Philippines may do off-and-on DST starting November

Last week Philippine House Deputy Minority Leader Arnel Ty urged President Aquino to declare daylight saving time from November to January and again from March to June, in an attempt to save electrical power. We had some obsolete commentary about a failed attempt to do something similar in 2006, and the attached commentary patch (installed in the experimental version) does some housekeeping in this area.