QoL Request: Start executable browsing in dir of old executable

[EatThePath]

When you hit browse on a mod's settings the first time after starting knossos, the navigation dialogue starts in the knossos install directory every time. If it instead started in the directory of the current selected executable, if there is one, it would save a lot of sanity for me at least. This is most relevant when having to switch between a lot of different experimental builds for testing purposes.