Mahout suite update

No jira for this. It clears a possible build failure but is primarily meant to automate tmp dir creation and deleting in scala tests. It adds a TmpDir name ("tmp/") and deletes it beforeAll tests in a suite then afterEach. It's in MahoutSuite. Work is done with java.io since it's only for scalatests and avoids importing libs or changing the pom.


it would seem to me tests for directory would be unnecessary. 

also recursion would probably be less circumlocutory if it were considered as deleting (any) resource rather than a directory, i.e.  something along the lines 

    def quietDelete(file:File) {
        for (nested <- file.listFiles) quietDelete(nested)
        try { file.delete }
    }

I am also not sure if try { } is actually necessary as this stuff will probably not produce an exception but rather returns false in case of failure. I don't remember already. Also i guess listFiles() may produce `null` under some circumstances, also not sure