Include slf4j no-op logger

Include in runtime slf4j's NOP logger instead of JDK logger

This avoids this error, which is saying it will use a NOP logger anyway:
```
2013-01-11 21:52:59 [SEVERE] SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
2013-01-11 21:52:59 [SEVERE] SLF4J: Defaulting to no-operation (NOP) logger implementation
2013-01-11 21:52:59 [SEVERE] SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
```
when using the current build on dev.bukkit.org (built with maven?)

and of course eliminates the "Announced new transaction" log messages that I get when running my build compiled with ant.