Add an eye to the JPasswordField in order to toggle masking character

[Blanco27]

I assume this would be a nice addition to the GUI, as many inexperienced users would appreciate this feature. Especially people that rarely ever use a keyboard. The same problematics described in #172 should probably be taken into consideration here as well.
I assume that if this added, it should be toggleable via the UIManager and disabled by default.

Here's what it could look like (This is our messy and hacky non-look-and-feel way of doing it):

[DevCharly]

Nice idea 👍

I'll add this later.
But first I need to extend FlatTextFieldUI so that it is possible to add icons/components to left and right sides of text field...

[Bios-Marcel]

Hey, do you already have some kind of API in mind and is it supposed to be something internal or something external?
I am assuming internal though, as adding public API to the UI class is probably not something you desire and this doesn't sound like something that makes sense via JComponent#putClientProperty.

I'd like to try working on this and fix #172 as well.

[DevCharly]

finally implemented in PR #442 😄