add "show chars" to allow people to see the typed password

[franzinc]

Issue #12 suggested this, but the change that closed that did not implement it.

Users here would definitely like this feature.

Thank you.

[jp-bennett]

I'm hesitant to allow easily exporting saved keys. The only way I'd be comfortable adding a "show characters" button is to track whether the config in question is new, or has been loaded from the database.

Would it be sufficient to have the option to show characters when first entering keys?

[franzinc]

I'm not sure we're talking about the same thing. I'm talking about seeing a password as it is typed, as an option. I realize that not showing the password as it is typed, by default, is best.