APLO-293: Improve failure handling in the case of a corrupted leveldb index.

We not attempt an index repair if the store fails to startup right.  And if it still fails after that the broker completes startup but the virtual host is put into a stopped status.

git-svn-id: https://svn.apache.org/repos/asf/activemq/activemq-apollo/trunk@1442638 13f79535-47bb-0310-9956-ffa450edef68