Please Trap Permission Denied Errors

[K-I-S-S]

Since JSSC 2.5.0
Added new exception TYPE_PERMISSION_DENIED. It can be very useful for _nix based system if user have no permissions for using serial device

Corollary: A web page when you search for "Permission Denied" telling the user what they need to do to fix it.

[ffissore]

Fixed. Fix will be available with next hourly build http://www.arduino.cc/en/Main/Software#hourly