get log level in App::LogAnyAdapter direct from D2 config instead of passing as arg from DocsLib; caller line in logger_engine->log is ignored so derived calling file from caller() and appended to message text; replaced deprecated Log::Any Callback method with Capture
reverted to earlier (uncommited) version of Log::Any function because most recently commited version was ignoring moinimum log level of tests (info), and presumably production (warnings) - note that use of Callback supposed to be deprecated in favour of Capture, but cannot make this method honour the min log-level setting
