The token login was introduced for the flash uploader. Since it has been
removed there is no need for this code anymore.

The motivation is to work around/fix issue #1182.

Using a CSP-Header did not work.

ToDo:
- [ ] Implement a check for Chrome only.

Autoloader should return true if it can handle the class so other registered autoloader don't execute.
require is faster than require_once and should be safe to use since the autoloader won't run if the class already exists

This allows to quickly check if a variable is empty but keeps strings
and numbers evaluating to zero.

Sorting by the sort number is too confusing since those are assigned
independently by different authors

You now can add labels that don't wrap around inputs, but you have to
ensure IDs are properly assigned yourself.

The Label class has been renamed to LabelElement to reflect the naming
scheme of the other elements.