This fixes a nasty graphical bug that occours when doors aren't placed at the edge of a non-scrolling scrollarea.
This basically allows you to place door blocks anywhere without worrying about anything to mess up.
- v1.1 fixes several issues related to me being bad at coding half a century ago.
- v1.2 implements a much better way of modifying an existing routine, which smoothly scrolls the screen into position until
the transition is performed. This version can be safely applied over the old one.

There's actually no need to use door asm to correct samus positioning. Use the Door Editors "Distance to Spawn" instead.

This still requires some more extensive testing, but for whomever it caused problems in the past, it should be fixed if you reapply this patch.
Uses free space at $82:F710