make generating the pacman-ps database on first install more reliable, as well as regenerating it if it doesn't exist on package upgrade

This reverts commit 8d7702da

Reduce variables in pacman-ps.  Also call mktemp to make a temp file and on exit delete the file if we are using a temp file.  Also get ready to put in a -h option. In addition add a -q (quiet) option to ps-lsof

no more temp files for pacman-ps :) Also this makes it much faster.  In addition, pacman-ps and ps-lsof no longer show the PROCESS FILENAME header for the columns if there is no output to be displayed (this looks much nicer and pacman-ps can now tell if ps-lsof hasn't outputted anything.  In this case we have no work to do in pacman-ps and saves us processing the package database.

add in preliminary pacman hook.  It works, but it will update the file list with pacman -Ql (lists every package not just ones we did nothing to on that pacman run) which is slow