Currently it can be quite difficult to track down some errors when misusing rpc.Register

Here's an extremely contrived example:

http://play.golang.org/p/DFgesPZmkV

changing the Register line to rpc.Register(&t) makes the code work because the
methods are defined on a pointer instead of a value receiver. Since according to the
net/rpc documentation the methods must have a pointer receiver I think the Register
function could provide a more informative message in this case. The current error
message "no exported methods of suitable type" implies there is something
wrong with the methods themselves whereas the real problem is the way the type is being
registered with the Register function.