add an option for setting the timezone in the local config.ini

I'd like to be able to specify the timezone in the config.ini for this app instead of the global php.ini.  Here is a proposed change that would allow that.

I understand from googleing around that the consensus "right way" to do this is to update the php.ini, but some users (myself included) may not have the authority to modify the php.ini, or it may be useful for different apps to be set to different timezones.