Get implemented on T instead of *T

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.

generic_binary.go

@@ -12,8 +12,8 @@ func (dst *GenericBinary) Set(src interface{}) error {
 	return (*Bytea)(dst).Set(src)
 }
 
-func (dst *GenericBinary) Get() interface{} {
-	return (*Bytea)(dst).Get()
+func (dst GenericBinary) Get() interface{} {
+	return (Bytea)(dst).Get()
 }
 
 func (src *GenericBinary) AssignTo(dst interface{}) error {