[Linux / XServer] Change focus on notification click

LOW PRIORITY.

when clicking a chat/join game notification on an xserver, the focus is not changed. Same applies to focus game.
Foremost can hopefully solved using JavaFX.
For the latter one there is as far as I can see no simple solution (No libraries except for a java binding of the C library of X, which is not worth the effort). We could just issue a (bash) command to "wmctrl -a Wine" which requires the user to install the wmctrl tool, but as installing on linux is something only people who are willing to go through some effort are gonna do, it shouldn't be a problem to tell them install another package from their package manager.