use cron instead of udev for low battery notification

udev not working with libnotify
added this to cron tab:
*/4 * * * * env DISPLAY=:0 /bin/sh ~/bin/battery-check.sh

as suggested here:
https://bbs.archlinux.org/viewtopic.php?pid=1372810#p1372810
move antigen to top so vimpager gets exported as pager

somewhere in omz lib/ less gets exported as the pager
add sudo to sanitize func
switch to slimlock on sleep with systemd

.no more two second delay to lock or running physlock in an xterm to try
to prevent it from just switching to the next tty!
.of course, I shouldn't have been using xss-lock in the
first place with physlock, but slimlock looks nice
.compiled from https://github.com/dannyn/slimlock since aur (slimlock-git) version's
password timeout is long no matter what you set