super-zaje: only try to download the image if it doesn't exist on local

FS

Note about installing debs and RPMs

Revisions to man

GoReleaser

postinst script to let the user know they should source zaje.sh so it…

… affects the

current session.

(Sourcing from postinst won't affect the session the package was
installed from)

Goreleaser: build Deb and RPM

README

pass `-L` to curl

`history` alias causes issues when history is invoked with args (say

`-a`). Comment out for now.

Apparently, in RHEL based distros, `which` reads aliases and function…

…s by default so

pass `--skip-alias --skip-functions` to prevent that.