#381 Don't display input passwords on Unix platform

[yokota]

Input password texts should not be echo back.
This patch disables local echo display when in input passwords as same as 7-Zip on Windows console version.

This patch was already included in "7zip" package for Debian GNU/Linux.

[John Doca]

I am as well interested in this feature for MacOS.

[yokota]

@ipavlov

Disabling local echo display is useful when input passwords.
Please consider this patch for Unix/Linux/macOS platforms.