Previously Set would always return an error when called on a range type.
Now it will accept an instance of itself, a pointer to an instance of
itself, a string, or nil. Strings are parsed with the same logic as
DecodeText.
Methods defined on T are also available on *T. Thought this technically
changes the interface, because *T will be automatically dereferenced as
needed it shouldn't be a breaking change.
See a8802b16cc for similar change.
They now take ownership of the src argument.
Needed to change Scan to make a copy of []byte arguments as lib/pq apparently
gives Scan a shared memory buffer.
Jack Christensen