Issue #42: Preventing Splitlog from creating a cycle in app-server logs

This pull request fixes issue #42 in multiple ways:

- It introduces gating condition on ```LogWatchBuilder``` to prevent unwanted messages from entering ```MessageConsumer```s. However, this is not nearly enough to avoid the problem of the cycle.
- Therefore it also introduces a proxy for SLF4J's ```Logger``` that will, by default, disable any Splitlog logging from being propagated into SLF4J.