Fixed self connections getting stretched by strategically placed edges in same block.

This edges that had the "bracket opening" or "bracket closing" shape (like in a self connection) could be manipulated to be on the wrong side of a passing by edge. This allowed the edge to get "stuck" on the wrong side of the edge and moved indefinitely away from it's owner box.
This bug was caused by a value being set by being passed to a function (as in C++ it was a pointer to an int) but in JS it hadn't been updated to being set by returning a value (as it would not be set otherwise as it was simply passing 'undefined' as an argument and had no connection to the previous variable upon entering the function).