trace option complete implementation

trace option permit to create a real stacktrace including the line where method was called.
Even if this is not enable by default, because of performance problems, this is a formidable debugging option.

Problem is implementation works great with connection methods, but not so much on pools / clusters, problem then beeing that callstack doesn't indicate application caller line, connection methods beeing already asynchronous.

The goal is - when option is enabled - implementation always indicate application caller line whatever the connector method is called.