Optimise finding game files

My first pull request ever so I might be doing this all wrong. Sorry for the messy duplicate commit, I forgot to add a comment made another commit for it, then realised that was a bad idea and tried to reset and it all went wrong. Anyway I just added in a method to check the default location for the game files before starting the search, I also added the users directory to the ignore list because who would install MWO into their user folder? Is this okay?