Print trace only on specific log level

[Mrucznik]

It would be cool if we could define, in which log level traces will be printed.
For example:

SetLogTraceLevel(logger, ERROR, true);
Log(logger, ERROR, "test"); //would print trace
Log(logger, INFO, "test"); //shouldn't print trace

[maddinat0r]

Having a per-logger per-loglevel setting would just clutter the config file, but I could add a global per-loglevel setting for this:

LogLevel: # per loglevel settings
  Error:
    PrintCallTrace: false