update changelog

sanitize fields and add extra checks

Add K_USRREG_ALLOWED_GROUPS configuration entry to limit the registration groups.

Sanitize XML output

Update TCPDF

update tcpdf

Fix some PHP 8.4 deprecations

update copyright year

Update session handler - requires PHP 7+

Bump version

Fix default values

Remove F_stripslashes_formfields function

Update TCExam website link

Fix TCExam website link

Update TCECode parsing to avoid XSS.