Improve internal trace logging

An earlier request in Byteman-151 has been expanded into a desire to improve the current verbose trace option which is a simple switch enabling printouts to System.out notifying Byteman activity. The idea is to replace it with a more finely configurable and, optionally, more noisy trace capability, making it easier to see what different parts of the Byteman code base are doing when errors happen or rules fail to work as expected.

This is a good starter task because a major part of it involves tracking control flow through the whole code base, identifying significant events which might need reporting and classifying them into categories for reporting or excluding. It does also involve some significant reqts+design work: to identify and categorize which events to trace, to determine how to allow users to configure tracing and to work out how to support efficient tracing without affecting thread timings.

One constraint on the implementation is that it rely on hand-rolled code and avoid using packages like log4j. It is better, as far as possible, to avoid the use of classes which a user might want to inject into.