I have a custom X11 keyboard layout that I can use with
setxkbmap. But after some searching I've found that apparently just having the XKB layout file isn't enough to set it as a new keyboard layout in KDE 4. What I would like to have my custom layout be recognized by the KDE system so that I can choose it using the systray applet, or install it as the default using the System Settings module. What do I need to do to make this happen? If it's complicated, that's fine, I would still like to know what is involved.
I've looked at this question which seemed to be related, but it apparently is about creating the keyboard layout in the first place, which I've already done.