Strong type the copyright frame

[JeevanJames]

Instead of having a string for the copyright value and expecting consumers to understand its conventions, use two properties for the year (integer) and the copyright message.

tag.Copyright.Year = 1977;
tag.Copyright.Message = "Aerosmith";

Since these two properties are mandatory, there would not be any default property, and hence no need for an implicit cast operator for the default value to frame instance.

I'm also not sure of the frame having the ability to output the complete copyright string (i.e. Copyright (c) 1977 Aerosmith). This is not localized and will not be useful for any language other than English. Instead, leave it to the consumer to construct the string.

However, as per the spec, it would be useful to have a read-only property that can combine the Year and Message properties correctly.