#19 Define logging/tracing framework

[Andrei Kapustin]

Frequently, an application needs to log its activities.
This is especially important during debugging, although
some long may also need to be written by release builds.

It is important to be able to control the logging
detail level and other logging framework features at
both compile- and run-time. For example, a debug build
may allow all logs to be written at runtime, while the
release builds only allows several simple logging
options to be configured at runtime.

Think about it.