Translate windows timezones into Timezone DB timezones using the CLDR map

Summary:
Ref T11816. This uses the Unicode/CLDR map to translate Windows timezone names into Timezone DB timezone names.

http://www.unicode.org/cldr/charts/29/supplemental/zone_tzid.html

Test Plan: Imported an event in "Russia Time Zone 10".

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11816

Differential Revision: https://secure.phabricator.com/D16877