Support using Konsole as default terminal emulator

[Ryan Thompson <rct thompsonclan org>]

I've created a small patch for Kupfer to support Konsole for actions
that require a terminal such as "Run in terminal".

I submitted a pull request on Kupfer's GitHub repo, which you can view
here: https://github.com/engla/kupfer/pull/7

The link directly to the branch is here:
https://github.com/DarwinAwardWinner/kupfer/tree/patch-1