XD-1775 & XD-1781 HdfsJdbc, HdfsMongo Accept Tests

Should mention mongodb not just the generic 'database', however, HdfsMongoDbJob itself seems to have an error, it catches NullPointerException not IllegalStateException.  In order to preserve the information of what failed, hdfsMongoDbjob.isReady should just delegate to AvailablesocketPorts.ensureReady.