I could have written `owner = this`, but I felt it...

# tornadofx

[edvin]

I could have written owner = this, but I felt it was best to make it clear that this means the button, that's why I wrote owner = this@button. This last snippet also shows an important feature. Even though I open the window over a specific Node, it can still be dragged outside. If people care about this, we can add an option to restrict the window to the bounds of the owner Node.