Custom Logger

Hi Sam and other contributors, Great job. Keep it up!

I have a feature suggestion. Would be nice to be able to provide a log listener and a log level. It's useful in cases when you want to collect and send logs to the server, and you use for this a custom logger. So it can be something like this:

Glide.get(this)
    .setLogLevel(FULL)
    .setLogListener(new LogListener() {
        @Override
        public void log(String message) {
        }
}

Or maybe something more precise:

public void log(LogLevel level, String message)