The new TableView's visible columns' x position is indeterminable

Steps to reproduce:

• Run the example project
• Scroll slowly from left to right end, observe the table view is displaying the right most columns, and the following state of the table view:
  • originX: 0
  • contentX: 2884
  • contentWidth: 3524
  • viewportWidth: 640
• Now scroll quickly from left to right end (using a trackpad or by clicking the right end of the scroll bar), there is a chance that the table view is now displaying the right most columns followed by a blank area, while the following state of the table view is identical to the above case:
  • originX: 0
  • contentX: 2884
  • contentWidth: 3524
  • viewportWidth: 640

Expected Result:

• The columns' x position should always be the same even when the TableView is scrolled quickly
• No blank area should be displayed on the right end of the TableView

Notes:

• This is only happening when the columns' width are variable, it won't happen if all columns are with the same width
• Setting the contentWidth of the TableView explicitly makes the issue more noticeable (i.e. easier to reproduce), without setting the contentWidth the issue is harder to reproduce and the TableView recovers from the state after a short amount of time (it slowly moves back to the normal position)
• boundsBehaviour has been set to Flickable.StopAtBounds