Make Settings Portable

Changed settings to use file instead of the Registry.  If the "IsPortable" application setting is set to True, the file will be stored with the executable.  Otherwise, it will be stored in the user's appdata path.  

The other change is to add a parameter to Nugget.sh to run the same command without using mono.  Some systems don't have Mono and they don't have the package extension and don't have admin access to install it.

I hope this attempt is better than the previous one.  Let me know if there is anything could be done better.