Obsolete:MNET 1.0 RPC

As part of the [Community hub] infrastructure, we need to define RPC calling conventions...

Moodle's APIs follow several principles that make them scalable annd flexible.

• They are "Just In Time discoverable" rather than all registered at runtime. This is a good optimization for HTTP's statelesness.
• Once an entry point is hit (a webpage in moodle, for instance) the module code author is in control. The framework doesn't limit what kinds of interactions can happen.

So we want to preserve those capabilities... Additionally, we want to make sure the RPC calls are safe, and cannot be exposed by accident.