Fixed/Implemented: replaced intval() by $app->functions->intval() in all interface functions due to big number problem in intval()

Implemented:  FS#2422 - Use domain module when creating subdomains 
Bugfix: datalog was used in the wrong way on editing aliasdomains
Bugfix: missing datalog update for parent domain on editing subdomains

Improved client and reseller limit checks

Data records are now assigned to the correct client group if they were created by the administrator.

- Changed shell of website linux user to /bin/false