TODO

-   Create layered Connection classes - one for stream and one for datagram
    transports.  I think buffered reads and non-buffered writes are the
    best answer - UDP needs exactly one write per procedure call, and 
    single-threaded operation needs every procedure call to get written
    before it waits for the answer.  Only multi-threaded mode can benefit
    from buffered writes at all, and then only under load.  I'll burn
    that bridge when I come to it.

-   Flesh out the RPC engine - more error checking.

-   Add a set of exception classes.

-   Finish all the function template objects.

-   Finish the marshal specializations - most of them still need
    toNet and fromNet.

-   Add support for additional data types - std::string, Buffer (for
    char* arguments), STL containers, etc.

-   Split the offset and allocated flags into a DataBuffer class, so
    Buffer can be just for char* arguments (just pointer and length).

-   Add multi-threaded mode.

-   See if there's a way to make the RPC methods actual class member
    functions.