* 1 - Netstring to transfer method name and result easily; like LineOnlyReceiver, but different.
** client has callRemote method; server accepts method names, calls them, returns result
** result is used to fire the callRemote's returned Deferred
* 2 - Two classes is clumsy and asymmetric; tag method calls and answers differently so one protocol can support both
* 3 - Support multiple calls at once (pipelining); use a deque of Deferreds instead of one Deferred.  Supports calls in either direction.
* 4 - Support Deferreds being returned from remote_* methods
** introduces a problem; what if the Deferreds fire in the wrong order?
** demonstrate by swapping the deferLater delays to make them fire in the wrong order.
* 5 - Include an id with call/answer messages and use a dict of Deferreds instead of a deque
** So far only string results are supported
* 6 - Banana can convert simple types to strings
** Better choice than pickle for security reasons
* 7 - Might as well use banana to encode the call/answer three-tuples as well
* 8 - Using banana for entire message makes it easy to add support for method arguments too
* 9 - More complicated types can't be encoded by banana though
** jelly turns more complicated types into simple types supported by banana
** pb_9.txt
* 10 - Split the application logic out from the protocol into a separate class
* 11 - Add cred support to allow the avatar to be changed
** Add an interface for the protocol's avatar, IRPC
*** Do the dynamic dispatch inside the avatar rather than in the protocol
** Add a login method to the protocol directly
*** Uses the portal to get a new avatar based on the supplied credentials
** Add a new kind of avatar with different remote methods
** Set up a portal with a realm that knows how to give out the right avatars
*** Login can accept multiple interfaces; realm can decide which one to return
**** different styles of handling multiple interfaces in realm
** Change app code to login and then call the importantStuff method