Aligned Nether Portal

Big update:

• Made the portal generation much more consistent with minecraft's code: from picked with direction is the center of the portal; to orientations
• The new algorithm to generate the portal fixes a ton of bugs that would arise when the overworld portal isn't the default size, or when you entered weirdly
• You have 11 seconds on the nether side to move out of the portal, or you will be sent back to the overworld and the terrain gets healed, to avoid getting trapped.
• Again, /trigger vanilla_nether_portals_for_you has existed to generate vanilla portals, if there isn't one on the nether-side already, but I made it even more obvious this time.

P.S. if the nether roof portal isn't working, make sure it's build exactly above the generated one