zones for German timezone history

[Alois Treindl]

I have compiled the zones for a complete timezone history of Germany.

I attach two files, one with the zone definitions, one with the output
of tzdump.

I would appreciate it if some group members could check the files for
correctness and completeness, and provide comments.

[Alois Treindl]

In file tzhist_germany.txt there is a typo, which needs to be corrected to:
# - In 1945, Berlin followed double summertime, together with the Soviet
zone