Allows a TaskActor to get type specific messages into it's next[T](t:T) method

This uses a Typeclass Handler[T] found in TaskActor to get specific types into a TaskActor's ```def next(t:T)``` method. These types are delivered via the Message.msg type which is defined to be ```<: java.io.Serializable```. A TaskActor must mix in MessageHandler[T] and define def next(t:T). For example:
```
class SOLBolt(conf : Configs) extends TaskActor(conf : Configs) with MessageHandler[Baz] {
...
  def next(baz: Baz): Unit = {...}
}
```
Additionally the TaskActor must include an implicit TypeClass like to following 
```
object SOLBolt {
  implicit object SOLBazHandler extends Handler[Baz](
  {
    case b:Baz =>
      b
  }
  )
}
```
A restriction is the TaskActor can't define multiple ```def next(t:T)``` methods if this particular TaskActor expects a variety of different types. This could probably be improved upon and should perhaps just deal with JSON types between TaskActor's.
Can we avoid add doNext() in interface?
It is somewhat confusing to have onNext, next, doNext at the same time.