Speed up S3A test runs

S3A Test runs are way too slow.

Speed them by

• reducing test setup/teardown costs
• eliminating obsolete test cases
• merge small tests into larger ones.

One thing i see is that the main S3A test cases create and destroy new FS instances; There's both a setup and teardown cost there, but it does guarantee better isolation.

Maybe if we know all test cases in a specific suite need the same options, we can manage that better; demand create the FS but only delete it in an @Afterclass method. That'd give us the OO-inheritance based setup of tests, but mean only one instance is done per suite