Update references to PropertyCheckConfiguration in generatorDrivenPropertyChecks

[lJoublanc]

There are a number of references to PropertyCheckConfig in generatorDrivenPropertyChecks.scala.html file; recent versions of scalacheck appear to use a new object, PropertyCheckConfiguration (note the suffix). The docs should be updated.

Also, it appears, though I'm not sure, that the examples have to be typed e.g.

  implicit override val generatorDrivenConfig: PropertyCheckConfiguration = ???

Otherwise the compiler complains recursive value generatorDrivenConfig needs type.