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

Fixed: password match function blocked tabs incorrectly
Fixed: set focus on username input field threw an error if this field did not exist on a page

Implemented: FS#1049 - Allow "Login as" also from the client list as it is allready possible from sysuser list.

It is now possible to redirect to a different url as result of the loadContent AJAX function

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