[slf4j-dev] Add Supplier args methods for Logger on java 8.

Hello. The java.util.function.Supplier is supported from Java 8. Some new methods like: public void debug(String format, Supplier<Object> argument); public void debug(String format, Supplier<Object>... arguments); may add to org.slf4j.Logger. Lazy computing improves performance. Old: log.info("INFO a {} b {}",JsonUtil.ObjectToJson(instance),"success"); New: log.info("INFO a {} b {}",()->JsonUtil.ObjectToJson(instance),"success"); The new one with better performance because the ObjectToJson called only on the info level or high. I found slf4j support jdk version older the 8. Maybe we can create a new module for JDK 8. Supplier on slf4j is really an exciting feature. Thanks!