ASL errata and Q&A with changebars 31

This is a compilation of official errata and Q&A from AH and MMP, plus older unofficial Q&A. I have tried not to overlap Klas's PerrySez compilation before version 29, but now I include it.
This file includes changebars, showing what has changed since the previous version.
There are other resources for A4 paper, and without the changebars.