Currently, we end up with two implementations of slf4j in Common via Avro's pom file.
Until AVRO-238 is released, we need to exclude slf4j-simple.
Avro's pom is inconsistent with Common's about SLF4J implementations
Log directly from jetty to commons logging, bypassing SLF4J
Multiple slf4j bindings cause warnings in HDFS.
Harmonize JAR library versions