Log level per compilation unit

[isherman]

• LOG_INFO, LOG_WARN, LOG_ERROR, LOG_CRITICAL macros are always defined and compiled.
• Log level output is toggled at runtime:
  • Default runtime log level is LogLevel::warning
  • One would use e.g. defaultLogger().setLogLevel(LogLevel::info); to enable lower log level - globally for all files at runtime.

If one need to enable noisy logs per compilation unit, this shall be done using the following mechanism:

#define FARM_LOG_LEVEL FARM_LOG_LEVEL_DEBUG
#include "farm_ng/core/logging/trace_debug_log.h"

Enabling such noisy log levels globally (and such macros in header files) is not supported. The rationale is that such noisy logging is not very helpful (too low signal to noise) and will most likely hurt performance to a degree that it makes debug execution too slow.