Prevent IE from generating unwanted clicks on the body. When mousedown fires on the selection element and then mouseup fires on the mask (because it is moved under the mouse during mousedown) then IE fires a click event on the body because it is the closest common ancestor. To prevent this, we detach and reatach the elements on mousedown which cancels the click event.
Merge pull request #1920 from jpotterm/prevent-ie-body-clicks

Prevent IE from generating unwanted clicks on the body.