* add new C# utility to generate timezone mappings
* update procedure to follow for updating timezones
* remove obsolete TimeZones.csx script
* update generated files with new tool
* Fix#4965: Adjusted the timezone update script to initialize
structs properly.
* Updated the scripts to generate the files directly
* Added a small HOWTO
* Split zone information to separate files to allow automatic
update without further manual editing.
Create a timezone.c file that does conform to C rules.