Clicking to select propagates to app, which can be awkward

[sudara]

A good example is a modal close button, where it's impossible to select the "done" button from the overlay (it can be selected from the tree, though).

Options:

• When overlay enabled, only propagate mouse clicks through the overlay once a selection has been made
• On hover, query if hovered components accepts clicks, if so, disable, renable on second mouse down

I don't think #49 is related. Meaning, even with overlay component moving disabled, this problem still exists.