Run directory config

[LeafHacker]

Is your feature request related to a problem? Please describe. We added the ability to configure the .minecraft directory with the intention that users might want to install Impact elsewhere, however the mojang launcher always uses the default .minecraft directory for a bunch of stuff we require, such as the libraries directory and launcher_profiles.json

Describe the solution you'd like Add a second box that configures where the installed profile should run, without affecting where to look for the .minecraft launcher directory.

Also remove the existing text box that configures the .minecraft directory, this should still be configurable from the command line.

Sidenote It seems likely that many third-party launchers also use mojang's .minecraft directory for things like libraries, we should consider this when we start to add support for them.