Make KCVSTest close() more robust on failure

This commit slighly reduces pointless NullPointerException noise in
tearDown when a subtest fails to setup its manager or store instances
Test Cassandra SSL authentication

This commit adds subclasses of AstyanaxStoreTest and ThriftStoreTest
that run all the same test logic, except with SSL enabled in the store
manager configuration.  Since cassandra.yaml needs certain config
options set to enable SSL and point it at its keystore, this also
required changes to the test harness.  The pom got new executions of
the resources and surefire plugins; these filter SSLized
cassandra.yaml into target/cassandra/conf/localhost-murmur-ssl/ and
also copy (without resource filtering) a truststore and keystore to
the same directory.  The keystore is used by cassandra.yaml and the
truststore is used by the Titan configurations in AstyanaxSSLStoreTest
and ThriftSSLStore_Test.

The Astyanax test passes, but the Thrift test fails due to multiple
bugs in the CTConnectionFactory.makeRawConnection's SSL logic.  It
should be calling setTrustStore instead of setKeyStore, and it needs
to check whether the transport is already open before trying to open
it.
Check TSocket.isOpen before attempting .open

`CTConnectionFactory.makeRawConnection` calls `new TSocket(hostname,
port, timeout)` when SSL is not enabled.  This returns an unopened
socket which `makeRawConnection` opens before returning.  However,
when SSL is enabled, `makeRawConnection` forgoes the constructor in
favor of calling `TSSLTransportFactory.getClientSocket` to build an
SSLized TSocket.  The TSocket it returns is already opened, and
attempting to reopen it throws an exception.

This commit makes opening conditional on `!isOpen()`.

I found similar code in Hector a useful sanity check:

https://github.com/hector-client/hector/blob/hector-2.0-0/core/src/main/java/me/prettyprint/cassandra/connection/client/HThriftClient.java#L174-L176
Use setTrustStore in Thrift's `makeRawConnection`

setKeyStore might be useful for two-way/mutual auth.  However, that
should be a separate set of config options with a separate method
invocation.  There's no way setKeyStore(cfg.sslTruststoreLocation,
cfg.sslTruststorePassword) was intentional when setKeyStore(same args)
is also available.