GUT message is misleading when no scripts are found

[bitwes]

GUT says "All tests passed!" when it can't find any scripts in the configured directories. At the very least the exclamation point should be changed to a question mark when it doesn't find any scripts. It should really be an error state, similar to when you specify a test name that cannot be found.

When GUT cannot find a script or test based on the filtering options it does not close the window if you have "exit when finished" set to true. The window should close. See #568.