Size of interface FB
Issue
When viewing the interface of a FB the interface is always positioned at the centre at a fixed size. Zooming does increase the size of the FB but since zooming is always to the top left corner, the FB moves to the bottom right. Furthermore since the artboard is maximally constrained, it is not possible to scroll to a position where the FB interface is in the centre again.
Issue
Allow arbitrary panning and zoom to either the FB or the cursor position (#4, #5)