Listen for mouse events on scrollView instead of renderedLines

It was not possible to click on the lower part of the last line
when the editor was scrollable and listening for mousedown events on renderedLines.

Closes #464

src/app/editor.coffee

@@ -835,13 +835,12 @@ class Editor extends View
       $(clickedElement).trigger(e)
       false if @isFocused
 
-    @renderedLines.on 'mousedown', '.fold.line', (e) =>
+    @scrollView.on 'mousedown', '.fold.line', (e) =>
       @destroyFold($(e.currentTarget).attr('fold-id'))
       false
 
-    onMouseDown = (e) =>
+    @scrollView.on 'mousedown', (e) =>
       clickCount = e.originalEvent.detail
-
       screenPosition = @screenPositionFromMouseEvent(e)
       if clickCount == 1
         if e.metaKey
@@ -857,8 +856,6 @@ class Editor extends View
 
       @selectOnMousemoveUntilMouseup() unless e.ctrlKey or e.originalEvent.which > 1
 
-    @renderedLines.on 'mousedown', onMouseDown
-
     @on "textInput", (e) =>
       @insertText(e.originalEvent.data)
       false