Fix TextView scrolling

scrollcontainer.go

@@ -200,6 +200,7 @@ func (this *ScrollContainer) handleKeyDown (key input.Key, numpad bool) bool {
 		} else {
 			vector.Y -= this.PageSize().Y
 		}
+		this.scrollBy(vector)
 		return true
 	case input.KeyPageDown:
 		if modifiers.Shift {
@@ -207,6 +208,7 @@ func (this *ScrollContainer) handleKeyDown (key input.Key, numpad bool) bool {
 		} else {
 			vector.Y += this.PageSize().Y
 		}
+		this.scrollBy(vector)
 		return true
 	}
 	return false

textview.go

@@ -22,6 +22,6 @@ func NewTextView (text string) *TextView {
 }
 
 func (this *TextView) handleScroll (x, y float64) bool {
-	this.ScrollTo(this.ContentBounds().Min.Add(image.Pt(int(x), int(y))))
+	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
 	return true
 }