Fix SetSavedFilesLocation for new builds

SetSavedFilesLocation was not done when a new default file location is generated.  The result is an assert failure when anything tests to use that location.  The settings menu is a good test for this.  I suggest clearing your settings to do this test.

There are more changes in the code but I believe they are unrelated.  There is a small chance that the qgc master code does not show this problem.

There is alot of junk in this pull request.  2a26695 is the only commit you need.  Just one line.
Also just as an FYI for the future: Changing a settings key will break everyones existing setting for this value. This one is so new it's fine though. Just wanted to make sure you know that. Nice to see someone else cranking away in the code. Thanks.