Adds a new setting for the gap size between tiles in a layout. Also
updates the resize handle calculations so they are dynamically generated
based on the gap size. Also updates the styling for the resize handles
to be more robust.
This also updates the default gap size to 3px.
This also slims out the Block Frame padding so it is just enough that
the blocks don't overlap when there's no gap.
Sylvie CroweandGitHub
sawka
Evan SimkowitzandGitHub