S-PHP Logger: Log messages of different error levels to files

This class can log messages of different error levels to files.

It can take a text message and write it to a log file along with the current date and time if the current message level is higher or equal than the minimum level.

The log message can append the caller object class and function names when it is called from an class function.

The log message is formmatted according to a template mask and have included the superglobal variables.