Optional SLF4J support without adding compile time dependency

Those changes were originally made by @BrynCooke in https://github.com/orientechnologies/orientdb/pull/1341.
This API version was used by original author of those changes and I did not change it because
we just ned the following from the api:
   compiled classes for org.slf4j.Logger & org.slf4j.LoggerFactory because of using following methods: 
   - LoggerFactory.getLogger(String)
   - Logger.info(String, Throwable)


I just realized that there is another issue all messages will be logged with INFO , Will change it and , since we will use number of Logger methods also change api version to the latest one.