User requested following feature:

"

For now, all child items of layout is managed by layout. 
However, sometimes,I don't want some child items in layout to be excluded from layout. 
For instance, when you put a MouseArea which covers an item,
usually you just put MouseArea in the item and set anchors.fill: parent. However, 
if you want to put a MouseArea which covers a Layout, you cannot put MouseArea in layout. 
For now, you have to make MouseArea sibling of layout and set anchors.fill: layout for instance 
and this is not intuitive. 

It would be much better to have such attached property Layout.floating or Layout.excludes,
so that the layout can ignore the item and then, 
you can put MouseArea as a child of layout and simply set anchors.fill: parent like in many other items. 
This suggestion also corresponds to positioners like Column/Row/Grid.

"