More of Orphis' dlist rewrite (signal handling)

Unfortunately, I think this breaks Qt's debugger, but I think Qt's still broken.  Sorry.  I don't think it'll be hard to fix, just need to use getList()...

This is again just Orphis' changes.  Gets rid of that warning in a bunch of games, and also:

 * Handles state more correctly when signals are used.
 * Runs signal handlers immediately before resuming the list.
 * Implements a fixed-size displaylist queue.
 * Implements dequeue (mainly interesting for stalled/etc. lists.)

At this point, there are some smaller changes that aren't merged in, but mostly it's just waits.

Couldn't find any games broken with this or hitting no DL ids left.

-[Unknown]