Allow two fences to be looped with the same loop.

With the improved lasso now allowing you to tie mobs in rows, I realize how many ways to use the lasso are still missing. 1) Tie the loop to different fences without needing to have a mob tied to it (this would be used for decoration such as creating railings, lampposts, and others). 2) Tie more than one rope to the same mob (example: now that the sulfur cube can glow when eating glowing blocks, I would really like to make string lights or those decorative string lights, but I can't make a line of mobs and tie the two ends to different fences). Adding this would also help with the decoration itself, but mainly with the creation of traps.