The goal of this is to be able to adapt the timezone form
in template without hacking the HTML already rendered.
* there are two arrays available:
* `continents` which contains only a list of available continents
* `cities` which contains a list of available timezone cities, associated with their continent
Note: there are two distinct array because RainTPL doesn't support nested loop very well.
Modifications
- attempt to use the server's timezone
- if none is set, use UTC
- TimeZone: apply coding conventions
- variable naming
- no closing PHP tag
Relates to #274
Signed-off-by: VirtualTam <virtualtam@flibidi.net>