Suggest substituting $password rather than obscuring

[jangari]

https://github.com/alecsammon/kpcli/blob/cbcd27cbd10ca5881bc47dd160d76f81467e2b6e/kpcli.pl#L1852

I see the point of obscuring the password with red on red, but this could be a security flaw if a user ran show and then quit, as the password would still be in their terminal buffer and could be copied. I've modified my copy so that each character is replaced by an asterisk when running show. Running show -f still shows plan text passwords.

PS, great program. I have basically replaced KeePassX with this.

[pepa65]

The colour-on-colour is handy for copying the password, but perhaps the screen terminal buffer should always be cleared on exit? (Is this possible??)