shell/aliases: move lsz and llz aliases out of ZSH-only section

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
Nicify shell code and fix some bash pitfalls

Replace $* with "$@", use 2>&1, and other minor changes.
Read http://bash.cumulonim.biz/BashPitfalls.html for more details about bash pitfalls

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
bin/ping6-local: output found IPv6 addresses in lowercase

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
bin/polyproxy: improve proxyfying ssh by not requiring socat

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>