Text: Remove replaceWholeText() which is deprecated

Closes scala-js#79

Author: tindzk

src/main/scala/org/scalajs/dom/lib.scala

@@ -4590,16 +4590,6 @@ class Text extends CharacterData {
  * MDN
  */
  def splitText(offset: Int): Text = js.native
-
- /**
- * The Text.replaceWholeText() method replaces the text of the node and all of its
- * logically adjacent text nodes with the specified text. The replaced nodes are
- * removed, including the current node, unless it was the recipient of the
- * replacement text.
- *
- * MDN
- */
- def replaceWholeText(content: String): Text = js.native
 }