remove purging of /usr/local/bin/concatfragments.sh

The hard coded path of `/usr/local/bin/concatfragments.sh` hasn't been
used for "a long time" so there's no reason to carry the cleanup around
any longer.
Merge pull request #86 from jhoblitt/remove_ancient_cleanup

remove purging of /usr/local/bin/concatfragments.sh