If Rubberduck.config cannot be read, use default configuration.

[rubberduck203]

If the *.config file is missing, Rubberduck uses a default configuration that is more or less hardcoded into the system and then later creates a new *.config file.

If *.config is simply corrupted, then Rubberduck blows up and the add-in doesn't load. Catch the exception and give the user the option to repair the *.config file with a warning that any customization will be lost.