Cross compile support for Scala 2.11

Note the use of `inner` here - anything else resulted in an NPE.

```
java.lang.NullPointerException
        at scala.tools.nsc.interpreter.ReplReporter.<init>(ReplReporter.scala:14)
        at com.nicta.scoobi.application.ScoobiILoop$$anon$2$$anon$3.<init>(ScoobiRepl.scala:153)
        at com.nicta.scoobi.application.ScoobiILoop$$anon$2.reporter$lzycompute(ScoobiRepl.scala:153)
        at com.nicta.scoobi.application.ScoobiILoop$$anon$2.reporter(ScoobiRepl.scala:153)
        at scala.tools.nsc.interpreter.IMain.<init>(IMain.scala:83)
        at scala.tools.nsc.interpreter.IMain.<init>(IMain.scala:101)
        at scala.tools.nsc.interpreter.ILoop$ILoopInterpreter.<init>(ILoop.scala:108)
        at com.nicta.scoobi.application.ScoobiILoop$$anon$2.<init>(ScoobiRepl.scala:144)
        at com.nicta.scoobi.application.ScoobiILoop.createInterpreter(ScoobiRepl.scala:144)
        at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:856)
        at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:854)
        at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:854)
        at scala.reflect.internal.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:95)
        at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:854)
```