Adding input from user home to Rainbow before saving project may break input path

[Former user]

Original [issue 1](https://code.google.com/p/okapi/issues/detail?id=1) created by @ysavourel on 2009-02-27T12:59:33.000Z:

If you create a new project (un-saved) in Rainbow add a file that is in the users' home (corresponding to the default root when un-saved), saving the project after to a different location breaks the path, as the auto-root in no longer the same.

On un-saved projects Rainbow needs to either force customized root whe adding a new file, or force the user to save.

[Former user]

Comment [3.](https://code.google.com/p/okapi/issues/detail?id=1#c3) originally posted by @ysavourel on 2009-03-02T13:36:07.000Z:

Both the root of the input list and the parameters folder are automatically changed to the directory of the file to add. Even when the file could have been using the default root of the unsaved project.

Later we may want to prompt the user to choose between doing this and saving the project.