How can I tell preview-latex to store all temporary files (especially the folder _region_.prv which contains the preview images) in /tmp and not in the folder of my actual .tex file, when I'm using it with AucTeX in emacs?
I checked the documentation and also looked in the customize-group of preview and auctex for a variable that allows me to select the directory for temporary files but without success. I know, that this question was already asked 3 years ago but without any real solution as far as I can tell. Maybe now 3 years later there is a solution for this?
In the case, that this really would not be possible, is there a way to delete all this preview related files (including the _region_.prv folder) on exiting the .tex file?