Timezone Bug

Fixed a bug where the timedatepicker would strip off the last three digits of timezones, even if the timezone code had 4 digits.  Address bug # 3182


Test by setting your timezone to Pacific/Auckland and go to the Homework Set Editor or Problem Set Detail page and click on one of the TimeDate pickers.  Without the patch the tz code should be ZDT with the patch it should be NZDT