The script is halted and a '500 Internal Server Error' is issued when a fatal error occurs.

Signed-off-by: Jesse van Assen <jesse.v.assen@gmail.com>
Script is killed with the proper exit code.
Added changelog entry.
Fix #2691
Fix #2515 (manually merge PR #2516)
Manually apply PR #2656

Fixes an 'Array to string conversion' notice in form_dropdown()
Add 'filename' to the return elements for create_captcha() (PR #2602)
Add CI_Upload:: option