-ChangeLog:
- Tickets: Improved security of ticket page
- Email: Check e-mail address spoofing in display name
- Billing: removed unique name check as article no. should only be unique
- Billing: paging in expense categories
- Files: Bug with moving files in contact permission denied while it should be allowed
- Core: added a disable and enable function for modules
- Core: debug info for adding new modules of finding modules