Support for Scala 2.11.2.

The recently released Scala 2.11.2 broke the PresentationReporter. The `Reporter.info()` method is now declared final and delegates to the `info0()` method with severity set to `INFO`. 

@aemoncannon do you think the "MissingRequirement" checks are still needed? I tried to come up with a way to reproduce that message but didn't have any luck.