bugfix: config/dev_machine/com.apple.PowerManagement.plist: disable the UPSShutdownAtLevel/UPSShutdownAtMinutesLeft functions because an orderly shutdown prevents the computer from auto-restarting on power loss
config/dev_machine/com.apple.PowerManagement.plist: UPSShutdownAtLevel: decreased to 5% to allow working longer on UPS power
config/dev_machine/com.apple.PowerManagement.plist: UPSShutdownAtMinutesLeft: decreased to 3 min to allow working longer on UPS power
added config/dev_machine/com.apple.PowerManagement.plist from /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist , so that this file can be easily restored when the system spuriously resets settings in it