[aquaria] Patch spam, again

[False.Genesis]

> Not speaking for anyone here, but I'd guess it would be easier to keep
> track of your changes if you would provide them as a hg repo (e.g. on
> bitbucket). Then it is easy to see what you did, impossible to miss a
> patch and very easy to merge (no need to merge, you just rebase it onto
> the tip and then someone can pull all changes).

Aaand I've gone ahead and done that:
https://bitbucket.org/fgenesis/aquaria

All prev. patches + some more are in, and I'll push more stuff there 
that I'd like to go into the official repo.
(I have 2 other repos on github for experimental stuff, but too bad hg 
can't pull from git, and I have been neglecting updating those.)

The thread pool patch may look like a bit overkill right now, but it 
really helps against stuttering (at least on WinXP). I'm sure it will 
also be handy for some HTTP networking stuff I had started about half a 
year ago; or to attempt backgrounding texture & some resource loading at 
some point.
(Have to admit that the first pool versions deadlocked under high load, 
but I think I got that sorted out. Managed to crash ogg vorbis once, 
probably overloaded the audio subsystem with too many decoder threads. 
No idea; seemed not related to the pool, though.)

Should I drop a note here when I have something new to pull, after my 
repo was merged? If all that gets in...

@Andrew: The obstruction grid fix you suggested is in, thanks for the idea.
- This obsoletes the fixed map files.