ACCUMULO-1556 Clarify initialization error for used fs

The Initialize class now generates clearer and more informative
error messages if an initialized instance is discovered. The
messages vary depending on whether instance.dfs.uri is used. The
values of instance.dfs.uri and instance.dfs.dir are also logged.
Merge branch '1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT
ACCUMULO-1556 Clarify initialization error for used fs

The Initialize class now generates clearer and more informative
error messages if an initialized instance is discovered. The
messages vary depending on whether instance.dfs.uri is used. The
values of instance.dfs.uri and instance.dfs.dir are also logged.
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT
ACCUMULO-1556 Clarify initialization error for used fs

The Initialize class now generates clearer and more informative
error messages if an initialized instance is discovered. The
messages vary depending on whether instance.dfs.uri is used. The
values of instance.dfs.uri and instance.dfs.dir are also logged.
Fixes "hostname -a" errors on OS X
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT
ACCUMULO-1947 Remove forcefully setting the logger in a test with no reset after the test is done.
ACCUMULO-1947 Use DfsConfigKeys.DFS_DATANODE_SYNCONCLOSE_KEY instead of the CreateFlag class as a better way to check
whether or not to we warn if the configuration doesn't contain dfs.datanode.synconclose=true
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java
	server/tserver/src/test/java/org/apache/accumulo/tserver/log/MultiReaderTest.java
ACCUMULO-802 Apply Sean Hickey's patch (v5)
ACCUMULO-802 Fixed NullPointerException during CloneTable due to loadbalancer trying to get the configuration before the namespace is put under the table in zookeeper. Fixed another NullPointerException with the -tn shell option for online, offline, and du. Added -tn option to shell config command. First attempt at adding a randomwalk test for namespaces, fails currently.
ACCUMULO-802 Updated ShellServer test with code that didnt fit in the patch correctly
ACCUMULO-802 Fixed a problem with RandomWalk's CloneTable, forgot to have it create a namespace. Randomwalk doesn't fail as fast, but still doesn't run correctly
ACCUMULO-802 Many small fixes. Largest change was adding CloneNamespace which clones all the tables in a namespace to a new namespace.
ACCUMULO-802 Lookup namespace config dynamically per table
ACCUMULO-802 Added global shell completion for table namespaces with -tn (just like -t for tables). Fixed problem with RenameTable to a new namespace copying over the old namespace configuration to the new table. Many other minor fixes. A few tests fail due to CloneTable not working until ACCUMULO-1565 is fixed
ACCUMULO-802 fixed an import problem in RenameTableNamespace. Commented out problematic code for cloning tables until ACCUMULO-1565 is fixed
ACCUMULO-802 added -tn option to the TablesCommand to allow listing of tables within a specific namespace
ACCUMULO-802 added a Total to the DUCommand to know the disk usage of a whole namespace or for everything