ACCUMULO-2411 Fix warnings in 1.5 branch

  Remove useless/no-op/broken javadocs and unused warnings. Isolate and
  suppress deprecation warning related to hadoop FileSystem replication
  support across HDFS versions.
Merge branch '1.5.1-SNAPSHOT' of https://git-wip-us.apache.org/repos/asf/accumulo into 1.5.1-SNAPSHOT
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	server/tserver/src/main/java/org/apache/accumulo/tserver/log/DfsLogger.java
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2291 CheckForMetadataProblems now checks the root table as well as the metadata table for problems. Also removed the fix option for the metadata table.

Signed-off-by: Christopher Tubbs <ctubbsii@apache.org>
ACCUMULO-2389 Removed the OfflineMetadataScanner and the offline option in the CheckForMetadataProblems.

Signed-off-by: Christopher Tubbs <ctubbsii@apache.org>
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-841 Remove unused imports