qos-ch/slf4j — pull request #70 by ouertani (2014-04-23 08:46:09+00:00)
Title: Add jdk 1.8 suppport 

Call by name (or lazy evaluation) will be accessible using Supplier of String. The example below :
```
logger.trace(() -> "trace msg "+echo()) ;
```
echo method and String concatenation will only be evaluation if trace level is enabled.