DebugLive: Show script debug information to authorized users

This class can be used to show script debug information to authorized users.

It can output script debugging information such as backtrace of the current point of the script that is executed including class names, function names and parameter values.

The debug output can be conditionally displayed depending on whether the current user access fingerprint is authorized. The fingerprint is a string computed from the user computer IP address and browser details.

The debug information can be outputted to the current page using the appropriate styles to hide it from the user, so the output information does not affect the page layout, but the developer may check the page HTML to view the output information.