I have two thumb buttons on my mice. In Windows (using MS or Logitech config software), can assign one as "Copy", and the other as "Paste"- or their keyboard shortcut equivalents: Ctrl-C, and Ctrl-V, respectively. I haven't been able to find out how to do this in Kubuntu (14.04).
Oddly, the desktop settings allows setting buttons to interact with the desktop, but the mouse settings (Settings | System Settings | Input Devices | Mouse) doesn't allow configuring those buttons to perform specified functions within applications.
