cloud-config supports a new plugin, called 'set-timezone', which
can be used to change the timezone on the underlying instance.
The patch adds a new method in the osutils abstraction, called `set_timezone`,
which should be implemented by each separated OS. The abstraction calls
into cloudbaseinit.utils.windows.timezone, another layer of abstraction
over two API methods, SetTimeZoneInformation for Windows 2003 and older
and SetDynamicTimeZoneInformation, for newer versions of Windows,
which also handles Daylight Saving Time.
The plugin supports standard IANA timezone names, which are then translated
to the Windows-specific timezone names, using tzlocal library.
Change-Id: I18674e1ae078fc69f3fb938065ba01a4de5464a1
b10917f9b0