Always verify nix store on install

Just wasted a couple hours chasing shadows because the nix store got
corrupted and there was no indication of that anywhere.

Since an install is one-time only, might as well verify.  Optimization
showed that the copied files aren't read-only; fixed that as well.

Also, use /bin/sh since there's a good chance that this script will be
run on systems without /bin/bash

0 files changed, 0 insertions, 0 deletions