Easy switch between region and window screenshot modes

Submitted by wolf

Assigned to Jérôme Guelfucci

Link to original bug (#13223)

Description

During a region screenshot on OS X, which is set with crosshairs (similar to XFCE's), the user can press the space bar to convert the crosshairs into a camera icon, which then highlights the window over which the cursor hovers. So when users click, it takes a screenshot of the selected window, but they can easily toggle between a region and window screenshot.

I used the feature all the time, and I believe it's more elegant than setting a separate keyboard shortcut. Wanted to propose it as a wish list feature request or at least see what others thought.