buildroot

zsh: security bump to version 5.0.7

Fixes shellshock-alike exploits.

Install binary to /bin as all shells should be and add hash file.

[Peter: drop /bin/sh handling as we're going to handle it globally]
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>