Refresh reminder list on save/delete

Allows modification of recipient/subject upon change from SMS to Email
Fixes email validation to allow lowercase letters
Fixes timestamp validation to allow for either Chrome or Firefox-style timestamps
Fixes timezones

Timezone element was not being added to login form causing database to always
use system time, which is incorrect
Adds perl file update_reminder which will interface with the system 'at' command
to execute reminders as specified by the user
Automatically opens new reminder on creation

Reminders backend returns ID on successful save in order to accurately determine
reminder to open
First version of reminder notification script
Fixes issues with "at" times and updating reminders in backend

Fixes validation of first field time in reminders