Dotless type application for infix operators.

When you have an aesthetic expresion like
```
  def f(xs: Iterator[Int]) = (
    xs takeWhile (_ < 1000)
             map (_ * -1)
          filter (_ % 2 == 0)
         flatMap (x => List(x, x))
    reduceOption (_ + _)
           maxBy (_.toString)
  )
```
And then for whatever reason you have to perform explicit
type application in the midst of that expression, it's
aggravating in the extreme that it has (had) to be rewritten
in its entirety to accommodate that change.

So now you can perform type application in the middle of it.

For reasons not entirely clear to me postfix operators are
excluded. The discussion as well as the approval for the infix
variation of it can be found at:
  https://groups.google.com/forum/#!msg/scala-language/eJl1wnkEz9M/hR984-lqC5EJ