ACCUMULO-2030 Clean up javadoc

  Fix ambiguous javadoc reference by removing it
  Remove incorrect exception declaration
  Remove unused import warning
ACCUMULO-2112 clear the bad server list of any server that is communicating
Merge branch '1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	server/src/main/java/org/apache/accumulo/server/master/Master.java
Merge branch '1.6.0-SNAPSHOT'
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/accumulo