Recursive rectangles

This is the first step towards widgets for the nodal interface. This very basic milestone involves a mouse-click event initiating a workflow to resolve the recipient of the click. This recipient then creates a sprite within its own bounds.

This example image of the recursive rectangles output based on the current peerd.c/interface.c shows the kind of sprites and their layout configuration as they're created. The current version of interface.c does not resolve a recipient, rather all sprites are created in the background (desktop) layer, the image above was made to show the recursive aspect with photoshop, but should be outputting this kind of structure natively very soon.