ACCUMULO-3341 Make deletetable remove any tables in the accumulo namespace before attempting deletion.

Also fixed the test package from 'command' to 'commands'.
ACCUMULO-3347 Log a message when a sesion is torn down due to it being idle or not accessed.
ACCUMULO-3351 Try to reset the writer if we don't have one but the table exists.

We have to avoid the case where we spin indefinitely trying to process
traces (but cannot because we don't have a writer). If we don't have
a writer, but the trace table exists, try to get a new writer.
ACCUMULO-3355 Catch the case when we find no traces and quit early.

If we don't quit early, we end up creating this absurd date and sending
it back to the user. Also fixed two tests that were unnecessarily
nuking the entire trace table. The Scanner they create is bounded for
their trace session; there is no reason to delete the rest of the records.
ACCUMULO-3167 Finally start working on moving MAC out of the IT base
ACCUMULO-3167 Move over SimpleMacITs to UnmanagedAccumuloIT
ACCUMULO-3167 Transition the rest of the SimpleMacITs over to UnmanagedAccumuloIT where possible
ACCUMULO-3167 Remove the rest of the SimpleMacIT tests and replace them with UnmanagedAccumuloIT

Made a new IT base class with no specifics on AccumuloClusters. Introduced
precedence for ITs to make their own MiniClusterHarness for starting a single
MAC instance instead of one per method.
ACCUMULO-3167 Move test setup classes out from the rest of the actual tests asserting things.
ACCUMULO-3167 Add a light wrapper to support a single MAC per test structure.
ACCUMULO-3167 Some more documentation on why the ShardMiniClusterIT even exists
ACCUMULO-3167 Move all of the harness code into its own package.
ACCUMULO-3167 First attempt at using Java properties to configure what type of AccumuloCluster is used
ACCUMULO-3167 Allow configuration of cluster to be specified via java properties file in addition to command line
ACCUMULO-3167 Remove deprecation warnings and have AuditMessageIT clean up itself before/after tests
ACCUMULO-3167 Add automatic table cleanup for tests which use uniqueNames()
ACCUMULO-3167 CleanUpIT doesn't play nicely with an existing instance.
ACCUMULO-3167 Move some tests back to MAC which are problematic
ACCUMULO-3167 More cleanup on table names to ensure a clean standalone system afterwards.
ACCUMULO-3167 Better error message