[Mono-list] Enum.IsDefined

[Alan Jenkins]

The ArgumentException should be "The value parameter is not the correct 
type.  It must be type String, or the Enum, or the same type as the 
underlying type of the Enum.", instead of  "The value parameter is not 
the correct type.  It must be type String, or the same type as the 
underlying type of the Enum.".  I have checked the message against the 
code and the msdn docs, although not against Microsofts implementation