add todo-ish comment and var which prints cpu core numbers
s/mytrimage/image_optim
say how we "can" kill the script
Merge remote-tracking branch 'remotes/stefanbeller/master'

Conflicts:
	image_optim.sh
xargs: don't spaw infinite processes but user cpu core number
Merge remote-tracking branch 'mainline/master'

Conflicts:
	image_optim.sh