A huge pull request...

...and bound to give some merging conflicts, but this has everything from launchernext in it. It also has the commits in my launcherui branch: I implemented .ui files for the launcher so I could re-use the GUI stuff for the filedialog in the editor. The file dialog itself is one monster commit, I forgot to do separate commits whilst I was fighting your editor code.

What's missing is support for the profiles, but at least it works for now. I must say that I'm still not entirely sure about your code. For example, the hiding/showing of dialogs is plain stupid, but at least it saves the user selection each instance.