ACCUMULO-1689 Ensure that the GC process isn't returned to the client.

Handled easily through a null check on the gcProcess as the config object is not
preserved inside of the minicluster. Added a test to make sure that we always
get a non-null Process (wrapped inside of each ProcessReference).
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
ACCUMULO-802 added iterators and constraints for namespaces. Currently the constraint part of the test fails, but iterators work.
ACCUMULO-802 working on namespace constraints, test currently fails, doesn't update tables constraints until something else triggers a reload.

Conflicts:
	server/src/main/java/org/apache/accumulo/server/conf/TableNamespaceConfiguration.java
	test/src/test/java/org/apache/accumulo/test/TableNamespacesTest.java
ACCUMULO-802 updated ConstraintCommand to work with namespaces
ACCUMULO-802 changed TableNamespaceConfiguration to update it's tables confs when it changes
ACCUMULO-802 added TableNamespaceConfWatcher
ACCUMULO-802 finished adding constraints to namespaces, works correctly.
ACCUMULO-802 removed useless line from testing
ACCUMULO-802 renamed TableNamespacesTest to an integration test: TableNamespacesIT
ACCUMULO-802 fixed tests to work correctly for cloning namespaces