Automatically break wiki lines at 72 chars

I got the config mixed up and setting nowrap causes lines to break
instead of wrapping. Now it's right.
Stop annoying on-close warnings for tex files

I had a cleanup autocommand for tex files which deletes aux, log, etc
files generated by pdf latex but if the files didn't exist it would give
warnings. Adding -f to rm stop it from complaining if the files don't
exist; problem solved!